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http://2012books.lardbucket.org/books/culture-and-media/s10-03-radio-s-impact-on-culture.html	Radio’s Impact on Culture	7.3 Radio’s Impact on Culture 7.3 Radio’s Impact on Culture Learning Objectives A New Kind of Mass Media War of the Worlds and the Power of Radio Radio and the Development of Popular Music Regional Sounds Take Hold Radio’s Lasting Influences Radio and Politics FDR’s Fireside Chats The Importance of Talk Radio Repeal of the Fairness Doctrine The Revitalization of AM Coast to Coast AM On-Air Political Influence Freedom of Speech and Radio Controversies Making (and Unmaking) a Career out of Controversy Key Takeaways Exercises	Radio’s Impact on Culture 7.3 Radio’s Impact on Culture Learning Objectives Analyze radio as a form of mass media. Describe the effects of radio on the spread of different types of music. Analyze the effects of the Fairness Doctrine on political radio. Formulate opinions on controversial issues in radio. Since its inception, radio’s impact on American culture has been immense. Modern popular culture is unthinkable without the early influence of radio. Entire genres of music that are now taken for granted, such as country and rock, owe their popularity and even existence to early radio programs that publicized new forms. A New Kind of Mass Media Mass media such as newspapers had been around for years before the existence of radio. In fact, radio was initially considered a kind of disembodied newspaper. Although this idea gave early proponents a useful, familiar way to think about radio, it underestimated radio’s power as a medium. Newspapers had the potential to reach a wide audience, but radio had the potential to reach almost everyone. Neither illiteracy nor even a busy schedule impeded radio’s success—one could now perform an activity and listen to the radio at the same time. This unprecedented reach made radio an instrument of social cohesion as it brought together members of different classes and backgrounds to experience the world as a nation. Radio programs reflected this nationwide cultural aspect of radio. Vox Pop, a show originally based on person-in-the-street interviews, was an early attempt to quantify the United States’ growing mass culture. Beginning in 1935, the program billed itself as an unrehearsed “cross-section of what the average person really knows” by asking random people an assortment of questions. Many modern television shows still employ this format not only for viewers’ amusement and information but also as an attempt to sum up national culture. Jason Loviglio, “Vox Pop: Network Radio and the Voice of the People” in Radio Reader: Essays in the Cultural History of Radio, ed. Michele Hilmes and Jason Loviglio (New York: Routledge, 2002), 89–106. Vox Pop functioned on a cultural level as an acknowledgement of radio’s entrance into people’s private lives to make them public. Ibid. Radio news was more than just a quick way to find out about events; it was a way for U.S. citizens to experience events with the same emotions. During the Ohio and Mississippi river floods of 1937, radio brought the voices of those who suffered as well as the voices of those who fought the rising tides. A West Virginia newspaper explained the strengths of radio in providing emotional voices during such crises: “Thanks to radio…the nation as a whole has had its nerves, its heart, its soul exposed to the needs of its unfortunates…We are a nation integrated and interdependent. We are ‘our brother’s keeper.’” Brown, Manipulating the Ether, 140. Radio’s presence in the home also heralded the evolution of consumer culture in the United States. In 1941, two-thirds of radio programs carried advertising. Radio allowed advertisers to sell products to a captive audience. This kind of mass marketing ushered in a new age of consumer culture. Cashman, America in the Twenties and Thirties, 329. War of the Worlds and the Power of Radio During the 1930s, radio’s impact and powerful social influence was perhaps most obvious in the aftermath of the Orson Welles’s notorious War of the Worlds broadcast. On Halloween night in 1938, radio producer Orson Welles told listeners of the Mercury Theatre on the Air that they would be treated to an original adaptation of H. G. Wells’s classic science fiction novel of alien invasion War of the Worlds. The adaptation started as if it were a normal music show that was interrupted by news reports of an alien invasion. Many listeners had tuned in late and did not hear the disclaimer, and so were caught up by the realism of the adaptation, believing it to be an actual news story. Figure 7.5 Orson Welles’s War of the Worlds broadcast terrified listeners, many of whom actually believed a Martian invasion was actually occurring. According to some, an estimated 6 million people listened to the show, with an incredible 1.7 million believing it to be true. Alex Lubertozzi and Brian Holmsten, The War of the Worlds: Mars’ Invasion of Earth, Inciting Panic and Inspiring Terror From H. G. Wells to Orson Welles and Beyond (Naperville, IL: Sourcebooks, 2005), 7–9. Some listeners called loved ones to say goodbye or ran into the street armed with weapons to fight off the invading Martians of the radio play. Ibid. In Grovers Mill, New Jersey—where the supposed invasion began—some listeners reported nonexistent fires and fired gunshots at a water tower thought to be a Martian landing craft. One listener drove through his own garage door in a rush to escape the area. Two Princeton University professors spent the night searching for the meteorite that had supposedly preceded the invasion. Ibid. As calls came in to local police stations, officers explained that they were equally concerned about the problem. Ibid. Although the story of the War of the Worlds broadcast may be funny in retrospect, the event traumatized those who believed the story. Individuals from every education level and walk of life had been taken in by the program, despite the producers’ warnings before, during the intermission, and after the program. Ibid. This event revealed the unquestioning faith that many Americans had in radio. Radio’s intimate communication style was a powerful force during the 1930s and 1940s. Radio and the Development of Popular Music One of radio’s most enduring legacies is its impact on music. Before radio, most popular songs were distributed through piano sheet music and word of mouth. This necessarily limited the types of music that could gain national prominence. Although recording technology had also emerged several decades before radio, music played live over the radio sounded better than it did on a record played in the home. Live music performances thus became a staple of early radio. Many performance venues had their own radio transmitters to broadcast live shows—for example, Harlem’s Cotton Club broadcast performances that CBS picked up and broadcast nationwide. Radio networks mainly played swing jazz, giving the bands and their leaders a widespread audience. Popular bandleaders including Duke Ellington, Benny Goodman, and Tommy Dorsey and their jazz bands became nationally famous through their radio performances, and a host of other jazz musicians flourished as radio made the genre nationally popular. Elijah Wald, How the Beatles Destroyed Rock ’n’ Roll: An Alternative History of American Popular Music (New York: Oxford University Press, 2009), 100–104. National networks also played classical music. Often presented in an educational context, this programming had a different tenor than did dance-band programming. NBC promoted the genre through shows such as the Music Appreciation Hour, which sought to educate both young people and the general public on the nuances of classical music. Sondra Wieland Howe, “The NBC Music Appreciation Hour: Radio Broadcasts of Walter Damrosch, 1928–1942,” Journal of Research in Music Education 51, no. 1 (Spring 2003). It created the NBC Symphony Orchestra, a 92-piece band under the direction of famed conductor Arturo Toscanini. The orchestra made its first performance in 1937 and was so popular that Toscanini stayed on as conductor for 17 years. Joseph Horowitz, Classical Music in America: A History of Its Rise and Fall (New York: Norton, 2005), 399–404. The Metropolitan Opera was also popular; its broadcasts in the early 1930s had an audience of 9 million listeners. Ibid., 364. Regional Sounds Take Hold The promotional power of radio also gave regional music an immense boost. Local stations often carried their own programs featuring the popular music of the area. Stations such as Nashville, Tennessee’s WSM played early country, blues, and folk artists. The history of this station illustrates the ways in which radio—and its wide range of broadcasting—created new perspectives on American culture. In 1927, WSM’s program Barn Dance, which featured early country music and blues, followed an hour-long program of classical music. George Hay, the host of Barn Dance, used the juxtaposition of classical and country genres to spontaneously rename the show: “For the past hour we have been listening to music taken largely from Grand Opera, but from now on we will present ‘The Grand Ole Opry.’” Louis Kyriakoudes, The Social Origins of the Urban South: Race, Gender, and Migration in Nashville and Middle Tennessee, 1890–1930 (Chapel Hill: University of North Carolina Press, 2003), 7. NBC picked up the program for national syndication in 1939, and it is currently one of the longest-running radio programs of all time. Figure 7.6 The Grand Ole Opry gave a national stage to country and early rock musicians. Shreveport, Louisiana’s KWKH aired an Opry -type show called Louisiana Hayride. This program propelled stars such as Hank Williams into the national spotlight. Country music, formerly a mix of folk, blues, and mountain music, was made into a genre that was accessible by the nation through this show. Without programs that featured these country and blues artists, Elvis Presley and Johnny Cash would not have become national stars, and country music may not have risen to become a popular genre. Nate DiMeo, “New York Clashes with the Heartland,” Hearing America: A Century of Music on the Radio, American Public Media, 2010, http://americanradioworks.publicradio.org/features/radio/b1.html. In the 1940s, other Southern stations also began playing rhythm and blues records recorded by Black artists. Artists such as Wynonie Harris, famous for his rendition of Roy Brown’s “Good Rockin’ Tonight,” were often played by White disc jockeys who tried to imitate Black Southerners. Tracey Laird, Louisiana Hayride: Radio and Roots Music Along the Red River (New York: Oxford University Press, 2005), 4–10. During the late 1940s, both Memphis, Tennessee’s WDIA and Atlanta, Georgia’s WERD were owned and operated by Black individuals. These disc jockeys often provided a measure of community leadership at a time when few Black individuals were in powerful positions. Walker, Rebels on the Air, 53–54. Radio’s Lasting Influences Radio technology changed the way that dance and popular music were performed. Because of the use of microphones, vocalists could be heard better over the band, allowing singers to use a greater vocal range and create more expressive styles, an innovation that led singers to become an important part of popular music’s image. The use of microphones similarly allowed individual performers to be featured playing solos and lead parts, features that were less encouraged before radio. The exposure of radio also led to more rapid turnover in popular music. Before radio, jazz bands played the same arrangement for several years without it getting old, but as radio broadcasts reached wide audiences, new arrangements and songs had to be produced at a more rapid pace to keep up with changing tastes. Wald, Beatles Destroyed Rock ’n’ Roll, 95–96. The spotlight of radio allowed the personalities of artists to come to the forefront of popular music, giving them newfound notoriety. Phil Harris, the bandleader from the Jack Benny Show, became the star of his own program. Other famous musicians used radio talent shows to gain fame. Popular programs such as Major Bowes and His Original Amateur Hour featured unknown entertainers trying to gain fame through exposure to the show’s large audience. Major Bowes used a gong to usher bad performers offstage, often contemptuously dismissing them, but not all the performers struck out; such successful singers as Frank Sinatra debuted on the program. Sterling and Kitross, Stay Tuned, 182. Television, much like modern popular music, owes a significant debt to the Golden Age of Radio. Major radio networks such as NBC, ABC, and CBS became—and remain—major forces in television, and their programming decisions for radio formed the basis for television. Actors, writers, and directors who worked in radio simply transferred their talents into the world of early television, using the successes of radio as their models. Radio and Politics Over the years, radio has had a considerable influence on the political landscape of the United States. In the past, government leaders relied on radio to convey messages to the public, such as President Franklin D. Roosevelt’s “fireside chats.” Radio was also used as a way to generate propaganda for World War II. The War Department established a Radio Division in its Bureau of Public Relations as early as 1941. Programs such as the Treasury Hour used radio drama to raise revenue through the sale of war bonds, but other government efforts took a decidedly political turn. Norman Corwin’s This Is War! was funded by the federal Office of Facts and Figures (OFF) to directly garner support for the war effort. It featured programs that prepared listeners to make personal sacrifices—including death—to win the war. The program was also directly political, popularizing the idea that the New Deal was a success and bolstering Roosevelt’s image through comparisons with Lincoln. Horten, Radio Goes to War, 45–47. FDR’s Fireside Chats Figure 7.7 During his presidency, Franklin D. Roosevelt delivered fireside chats, a series of radio broadcasts in which he spoke directly to the American people. President Franklin D. Roosevelt’s Depression-era radio talks, or “fireside chats,” remain one of the most famous uses of radio in politics. While governor of New York, Roosevelt had used radio as a political tool, so he quickly adopted it to explain the unprecedented actions that his administration was taking to deal with the economic fallout of the Great Depression. His first speech took place only 1 week after being inaugurated. Roosevelt had closed all of the banks in the country for 4 days while the government dealt with a national banking crisis, and he used the radio to explain his actions directly to the American people. John Grafton, ed., Great Speeches—Franklin Delano Roosevelt (Mineola, NY: Dover, 1999), 34. Roosevelt’s first radio address set a distinct tone as he employed informal speech in the hopes of inspiring confidence in the American people and of helping them stave off the kind of panic that could have destroyed the entire banking system. Roosevelt understood both the intimacy of radio and its powerful outreach. Ibid. He was thus able to balance a personal tone with a message that was meant for millions of people. This relaxed approach inspired a CBS executive to name the series the “fireside chats.” Ibid. Roosevelt delivered a total of 27 of these 15- to 30-minute-long addresses to estimated audiences of 30 million to 40 million people, then a quarter of the U.S. population. Ibid. Roosevelt’s use of radio was both a testament to his own skills and savvy as a politician and to the power and ubiquity of radio during this period. At the time, there was no other form of mass media that could have had the same effect. Certainly, radio has been used by the government for its own purposes, but it has had an even greater impact on politics by serving as what has been called “the ultimate arena for free speech.” Richard Davis and Diana Owen, New Media and American Politics (New York: Oxford University Press, 1998), 54. Such infamous radio firebrands as Father Charles Coughlin, a Roman Catholic priest whose radio program opposed the New Deal, criticized Jews, and supported Nazi policies, aptly demonstrated this capability early in radio’s history. Sterling and Kitross, Stay Tuned, 199. In recent decades, radio has supported political careers, including those of U.S. Senator Al Franken of Minnesota, former New York City mayor Rudy Giuliani, and presidential aspirant Fred Thompson. Talk show hosts such as Rush Limbaugh have gained great political influence, with some even viewing Limbaugh as the de facto leader of the Republican Party. Liz Halloran, “Steele-Limbaugh Spat: A Battle for GOP’s Future?” NPR, March 2, 2009, http://www.npr.org/templates/story/story.php?storyId=101430572. The Importance of Talk Radio An important contemporary convergence of radio and politics can be readily heard on modern talk radio programs. Far from being simply chat shows, the talk radio that became popular in the 1980s features a host who takes callers and discusses a wide assortment of topics. Talk radio hosts gain and keep their listeners by sheer force of personality, and some say shocking or insulting things to get their message across. These hosts range from conservative radio hosts such as Rush Limbaugh to so-called shock jocks such as Howard Stern. Repeal of the Fairness Doctrine While talk radio first began during the 1920s, the emergence of the format as a contemporary cultural and political force took place during the mid- to late-1980s following the repeal of the Fairness Doctrine. Gilbert Cruz, “GOP Rallies Behind Talk Radio,” Time, June 28, 2007, http://www.time.com/time/politics/article/0,8599,1638662,00.html. As you read earlier in this chapter, this doctrine, established in 1949, required any station broadcasting a political point of view over the air to allow equal time to all reasonable dissenting views. Despite its noble intentions of safeguarding public airwaves for diverse views, the doctrine had long attracted a level of dissent. Opponents of the Fairness Doctrine claimed that it had a chilling effect on political discourse as stations, rather than risk government intervention, avoided programs that were divisive or controversial. Ibid. In 1987, the FCC under the Reagan administration repealed the regulation, setting the stage for an AM talk radio boom; by 2004, the number of talk radio stations had increased by 17-fold. Brian Anderson, South Park Conservatives: The Revolt Against Liberal Media Bias (Washington D.C.: Regnery Publishing, 2005), 35–36. The end of the Fairness Doctrine allowed stations to broadcast programs without worrying about finding an opposing point of view to balance the stated opinions of its host. Radio hosts representing all points of the political spectrum could say anything that they wanted to—within FCC limits—without fear of rebuttal. Media bias and its ramifications will be explored at greater length in Chapter 14 "Ethics of Mass Media". The Revitalization of AM The migration of music stations to the FM spectrum during the 1960s and 1970s provided a great deal of space on the AM band for talk shows. With the Fairness Doctrine no longer a hindrance, these programs slowly gained notoriety during the late 1980s and early 1990s. In 1998, talk radio hosts railed against a proposed congressional pay increase, and their listeners became incensed; House Speaker Jim Wright received a deluge of faxes protesting it from irate talk radio listeners from stations all over the country. Douglas, Listening In, 287. Ultimately, Congress canceled the pay increase, and various print outlets acknowledged the influence of talk radio on the decision. Propelled by events such as these, talk radio stations rose from only 200 in the early 1980s to more than 850 in 1994. Ibid., 286–287. Coast to Coast AM Although political programs unquestionably rule AM talk radio, that dial is also home to a kind of show that some radio listeners may have never experienced. Late at night on AM radio, a program airs during which listeners hear stories about ghosts, alien abductions, and fantastic creatures. It’s not a fictional drama program, however, but instead a call-in talk show called Coast to Coast AM. In 2006, this unlikely success ranked among the top 10 AM talk radio programs in the nation—a stunning feat considering its 10 p.m. to 2 a.m. time slot and bizarre format. Delfin Vigil, “Conspiracy Theories Propel AM Radio Show Into the Top Ten,” San Francisco Chronicle, November 12, 2006, http://articles.sfgate.com/2006-11-12/news/17318973_1_radio-show-coast-cold-war. Originally started by host Art Bell in the 1980s, Coast to Coast focuses on topics that mainstream media outlets rarely treat seriously. Regular guests include ghost investigators, psychics, Bigfoot biographers, alien abductees, and deniers of the moon landing. The guests take calls from listeners who are allowed to ask questions or talk about their own paranormal experiences or theories. Coast to Coast ’s current host, George Noory, has continued the show’s format. In some areas, its ratings have even exceeded those of Rush Limbaugh’s. Ibid. For a late-night show, these kinds of high ratings are rare. The success of Coast to Coast is thus a continuing testament to the diversity and unexpected potential of radio. Ibid. On-Air Political Influence As talk radio’s popularity grew during the early 1990s, it quickly became an outlet for political ambitions. In 1992, nine talk show hosts ran for U.S. Congress. By the middle of the decade, it had become common for many former—or failed—politicians to attempt to use the format. Former California governor Jerry Brown and former New York mayor Ed Koch were among the mid-1990s politicians that had AM talk shows. Annenberg Public Policy Center, Call-In Political Talk Radio: Background, Content, Audiences, Portrayal in Mainstream Media, Annenberg Public Policy Center Report Series, August 7, 1996, http://www.annenbergpublicpolicycenter.org/Downloads/Political_Communication/Political_Talk_Radio/1996_03_political_talk_radio_rpt.PDF. Both conservatives and liberals widely agree that conservative hosts dominate AM talk radio. Many talk show hosts, such as Limbaugh, who began his popular program 1 year after the repeal of the Fairness Doctrine, have made a profitable business out of their programs. Figure 7.8 Talk radio shows increased dramatically in number and popularity in the wake of the 1987 repeal of the Fairness Doctrine. During the 2000s, AM talk radio continued to build. Hosts such as Michael Savage, Sean Hannity, and Bill O’Reilly furthered the trend of popular conservative talk shows, but liberal hosts also became popular through the short-lived Air America network. The network closed abruptly in 2010 amid financial concerns. Brian Stelter, “Liberal Radio, Even Without Air America,” New York Times, January 24, 2010, http://www.nytimes.com/2010/01/25/arts/25radio.html. Although the network was unsuccessful, it provided a platform for such hosts as MSNBC TV news host Rachel Maddow and Minnesota Senator Al Franken. Other liberal hosts such as Bill Press and Ron Reagan, son of President Ronald Reagan, have also found success in the AM political talk radio field. Ibid. Despite these successes, liberal talk radio is often viewed as unsustainable. Billy Hallowell, “Media Matters’ Vapid Response to Air America’s Crash,” Big Journalism, January 26, 2010, http://bigjournalism.com/bhallowell/2010/01/26/media-matters-vapid-response-to-air-americas-crash. To some, the failure of Air America confirms conservatives’ domination of AM radio. In response to the conservative dominance of talk radio, many prominent liberals, including House Speaker Nancy Pelosi, have advocated reinstating the Fairness Doctrine and forcing stations to offer equal time to contrasting opinions. Bethany Stotts, “Pelosi Supports Return of Fairness Doctrine,” Accuracy in Media Column, June 26, 2008, http://www.aim.org/aim-column/pelosi-support-return-of-fairness-doctrine. Freedom of Speech and Radio Controversies While the First Amendment of the U.S. Constitution gives radio personalities the freedom to say nearly anything they want on the air without fear of prosecution (except in cases of obscenity, slander, or incitement of violence, which will be discussed in greater detail in Chapter 15 "Media and Government" ), it does not protect them from being fired from their jobs when their controversial comments create a public outrage. Many talk radio hosts, such as Howard Stern, push the boundaries of acceptable speech to engage listeners and boost ratings, but sometimes radio hosts push too far, unleashing a storm of controversy. Making (and Unmaking) a Career out of Controversy Talk radio host Howard Stern has managed to build his career on creating controversy—despite being fined multiple times for indecency by the FCC, Stern remains one of highest-paid and most popular talk radio hosts in the United States. Stern’s radio broadcasts often feature scatological or sexual humor, creating an “anything goes” atmosphere. Because his on-air antics frequently generate controversy that can jeopardize advertising sponsorships and drive away offended listeners—in addition to risking fines from the FCC—Stern has a history of uneasy relationships with the radio stations that employ him. In an effort to free himself of conflicts with station owners and sponsors, in 2005 Stern signed a contract with Sirius Satellite Radio, which is exempt from FCC regulation, so that he can continue to broadcast his show without fear of censorship. Stern’s massive popularity gives him a lot of clout, which has allowed him to weather controversy and continue to have a successful career. Other radio hosts who have gotten themselves in trouble with poorly considered on-air comments have not been so lucky. In April 2007, Don Imus, host of the long-running Imus in the Morning, was suspended for racist and sexist comments made about the Rutgers University women’s basketball team. Imus in the Morning, MSNBC, April 4, 2007. Though he publically apologized, the scandal continued to draw negative attention in the media, and CBS canceled his show to avoid further unfavorable publicity and the withdrawal of advertisers. Though he returned to the airwaves in December of that year with a different station, the episode was a major setback for Imus’s career and his public image. Similarly, syndicated conservative talk show host Dr. Laura Schelssinger ended her radio show in 2010 due to pressure from radio stations and sponsors after her repeated use of a racial epithet on a broadcast incited a public backlash. Ibid. As the examples of these talk radio hosts show, the issue of freedom of speech on the airwaves is often complicated by the need for radio stations to be profitable. Outspoken or shocking radio hosts can draw in many listeners, attracting advertisers to sponsor their shows and bringing in money for their radio stations. Although some listeners may be offended by these hosts and may stop tuning in, as long as the hosts continue to attract advertising dollars, their employers are usually content to allow the hosts to speak freely on the air. However, if a host’s behavior ends up sparking a major controversy, causing advertisers to withdraw their sponsorship to avoid tarnishing their brands, the radio station will often fire the host and look to someone who can better sustain advertising partnerships. Radio hosts’ right to free speech does not compel their employer to give them the forum to exercise it. Popular hosts like Don Imus may find a home on the air again once the furor has died down, but for radio hosts concerned about the stability of their careers, the lesson is clear: there are practical limits on their freedom of speech. Key Takeaways Radio was unique as a form of mass media because it had the potential to reach anyone, even the illiterate. Radio news in the 1930s and 1940s brought the emotional impact of traumatic events home to the listening public in a way that gave the nation a sense of unity. Radio encouraged the growth of national popular music stars and brought regional sounds to wider audiences. The effects of early radio programs can be felt both in modern popular music and in television programming. The Fairness Doctrine was created to ensure fair coverage of issues over the airwaves. It stated that radio stations must give equal time to contrasting points of view on an issue. An enormous rise in the popularity of AM talk radio occurred after the repeal of the Fairness Doctrine in 1987. The need for radio stations to generate revenue places practical limits on what radio personalities can say on the air. Shock jocks like Howard Stern and Don Imus test, and sometimes exceed, these limits and become controversial figures, highlighting the tension between freedom of speech and the need for businesses to be profitable. Exercises Please respond to the following writing prompts. Each response should be a minimum of one paragraph. Describe the unique qualities that set radio apart from other forms of mass media, such as newspapers. How did radio bring new music to places that had never heard it before? Describe political talk radio before and after the Fairness Doctrine. What kind of effect did the Fairness Doctrine have? Do you think that the Fairness Doctrine should be reinstated? Explain your answer. Investigate the controversy surrounding Don Imus and the comments that led to his show’s cancellation. What is your opinion of his comments and CBS’s reaction to them?	msmarco_doc_00_11636933
http://2012books.lardbucket.org/books/economics-principles-v2.0/s13-02-the-monopoly-model.html	The Monopoly Model	10.2 The Monopoly Model 10.2 The Monopoly Model Learning Objectives Monopoly and Market Demand Total Revenue and Price Elasticity Demand and Marginal Revenue Monopoly Equilibrium: Applying the Marginal Decision Rule Heads Up! Key Takeaways Try It! Case in Point: Profit-Maximizing Sports Teams Answer to Try It! Problem	The Monopoly Model 10.2 The Monopoly Model Learning Objectives Explain the relationship between price and marginal revenue when a firm faces a downward-sloping demand curve. Explain the relationship between marginal revenue and elasticity along a linear demand curve. Apply the marginal decision rule to explain how a monopoly maximizes profit. Analyzing choices is a more complex challenge for a monopoly firm than for a perfectly competitive firm. After all, a competitive firm takes the market price as given and determines its profit-maximizing output. Because a monopoly has its market all to itself, it can determine not only its output but its price as well. What kinds of price and output choices will such a firm make? We will answer that question in the context of the marginal decision rule: a firm will produce additional units of a good until marginal revenue equals marginal cost. To apply that rule to a monopoly firm, we must first investigate the special relationship between demand and marginal revenue for a monopoly. Monopoly and Market Demand Because a monopoly firm has its market all to itself, it faces the market demand curve. Figure 10.2 "Perfect Competition Versus Monopoly" compares the demand situations faced by a monopoly and a perfectly competitive firm. In Panel (a), the equilibrium price for a perfectly competitive firm is determined by the intersection of the demand and supply curves. The market supply curve is found simply by summing the supply curves of individual firms. Those, in turn, consist of the portions of marginal cost curves that lie above the average variable cost curves. The marginal cost curve, MC, for a single firm is illustrated. Notice the break in the horizontal axis indicating that the quantity produced by a single firm is a trivially small fraction of the whole. In the perfectly competitive model, one firm has nothing to do with the determination of the market price. Each firm in a perfectly competitive industry faces a horizontal demand curve defined by the market price. Figure 10.2 Perfect Competition Versus Monopoly Panel (a) shows the determination of equilibrium price and output in a perfectly competitive market. A typical firm with marginal cost curve MC is a price taker, choosing to produce quantity q at the equilibrium price P. In Panel (b) a monopoly faces a downward-sloping market demand curve. As a profit maximizer, it determines its profit-maximizing output. Once it determines that quantity, however, the price at which it can sell that output is found from the demand curve. The monopoly firm can sell additional units only by lowering price. The perfectly competitive firm, by contrast, can sell any quantity it wants at the market price. Contrast the situation shown in Panel (a) with the one faced by the monopoly firm in Panel (b). Because it is the only supplier in the industry, the monopolist faces the downward-sloping market demand curve alone. It may choose to produce any quantity. But, unlike the perfectly competitive firm, which can sell all it wants at the going market price, a monopolist can sell a greater quantity only by cutting its price. Suppose, for example, that a monopoly firm can sell quantity Q1 units at a price P1 in Panel (b). If it wants to increase its output to Q2 units—and sell that quantity—it must reduce its price to P2. To sell quantity Q3 it would have to reduce the price to P3. The monopoly firm may choose its price and output, but it is restricted to a combination of price and output that lies on the demand curve. It could not, for example, charge price P1 and sell quantity Q3. To be a price setter, a firm must face a downward-sloping demand curve. Total Revenue and Price Elasticity A firm’s elasticity of demand with respect to price has important implications for assessing the impact of a price change on total revenue. Also, the price elasticity of demand can be different at different points on a firm’s demand curve. In this section, we shall see why a monopoly firm will always select a price in the elastic region of its demand curve. Suppose the demand curve facing a monopoly firm is given by Equation 10.1, where Q is the quantity demanded per unit of time and P is the price per unit: Equation 10.1 Q = 10 − P This demand equation implies the demand schedule shown in Figure 10.3 "Demand, Elasticity, and Total Revenue". Total revenue for each quantity equals the quantity times the price at which that quantity is demanded. The monopoly firm’s total revenue curve is given in Panel (b). Because a monopolist must cut the price of every unit in order to increase sales, total revenue does not always increase as output rises. In this case, total revenue reaches a maximum of $25 when 5 units are sold. Beyond 5 units, total revenue begins to decline. Figure 10.3 Demand, Elasticity, and Total Revenue Suppose a monopolist faces the downward-sloping demand curve shown in Panel (a). In order to increase the quantity sold, it must cut the price. Total revenue is found by multiplying the price and quantity sold at each price. Total revenue, plotted in Panel (b), is maximized at $25, when the quantity sold is 5 units and the price is $5. At that point on the demand curve, the price elasticity of demand equals −1. The demand curve in Panel (a) of Figure 10.3 "Demand, Elasticity, and Total Revenue" shows ranges of values of the price elasticity of demand. We have learned that price elasticity varies along a linear demand curve in a special way: Demand is price elastic at points in the upper half of the demand curve and price inelastic in the lower half of the demand curve. If demand is price elastic, a price reduction increases total revenue. To sell an additional unit, a monopoly firm must lower its price. The sale of one more unit will increase revenue because the percentage increase in the quantity demanded exceeds the percentage decrease in the price. The elastic range of the demand curve corresponds to the range over which the total revenue curve is rising in Panel (b) of Figure 10.3 "Demand, Elasticity, and Total Revenue". If demand is price inelastic, a price reduction reduces total revenue because the percentage increase in the quantity demanded is less than the percentage decrease in the price. Total revenue falls as the firm sells additional units over the inelastic range of the demand curve. The downward-sloping portion of the total revenue curve in Panel (b) corresponds to the inelastic range of the demand curve. Finally, recall that the midpoint of a linear demand curve is the point at which demand becomes unit price elastic. That point on the total revenue curve in Panel (b) corresponds to the point at which total revenue reaches a maximum. The relationship among price elasticity, demand, and total revenue has an important implication for the selection of the profit-maximizing price and output: A monopoly firm will never choose a price and output in the inelastic range of the demand curve. Suppose, for example, that the monopoly firm represented in Figure 10.3 "Demand, Elasticity, and Total Revenue" is charging $3 and selling 7 units. Its total revenue is thus $21. Because this combination is in the inelastic portion of the demand curve, the firm could increase its total revenue by raising its price. It could, at the same time, reduce its total cost. Raising price means reducing output; a reduction in output would reduce total cost. If the firm is operating in the inelastic range of its demand curve, then it is not maximizing profits. The firm could earn a higher profit by raising price and reducing output. It will continue to raise its price until it is in the elastic portion of its demand curve. A profit-maximizing monopoly firm will therefore select a price and output combination in the elastic range of its demand curve. Of course, the firm could choose a point at which demand is unit price elastic. At that point, total revenue is maximized. But the firm seeks to maximize profit, not total revenue. A solution that maximizes total revenue will not maximize profit unless marginal cost is zero. Demand and Marginal Revenue In the perfectly competitive case, the additional revenue a firm gains from selling an additional unit—its marginal revenue—is equal to the market price. The firm’s demand curve, which is a horizontal line at the market price, is also its marginal revenue curve. But a monopoly firm can sell an additional unit only by lowering the price. That fact complicates the relationship between the monopoly’s demand curve and its marginal revenue. Suppose the firm in Figure 10.3 "Demand, Elasticity, and Total Revenue" sells 2 units at a price of $8 per unit. Its total revenue is $16. Now it wants to sell a third unit and wants to know the marginal revenue of that unit. To sell 3 units rather than 2, the firm must lower its price to $7 per unit. Total revenue rises to $21. The marginal revenue of the third unit is thus $5. But the price at which the firm sells 3 units is $7. Marginal revenue is less than price. To see why the marginal revenue of the third unit is less than its price, we need to examine more carefully how the sale of that unit affects the firm’s revenues. The firm brings in $7 from the sale of the third unit. But selling the third unit required the firm to charge a price of $7 instead of the $8 the firm was charging for 2 units. Now the firm receives less for the first 2 units. The marginal revenue of the third unit is the $7 the firm receives for that unit minus the $1 reduction in revenue for each of the first two units. The marginal revenue of the third unit is thus $5. (In this chapter we assume that the monopoly firm sells all units of output at the same price. In the next chapter, we will look at cases in which firms charge different prices to different customers.) Marginal revenue is less than price for the monopoly firm. Figure 10.4 "Demand and Marginal Revenue" shows the relationship between demand and marginal revenue, based on the demand curve introduced in Figure 10.3 "Demand, Elasticity, and Total Revenue". As always, we follow the convention of plotting marginal values at the midpoints of the intervals. Figure 10.4 Demand and Marginal Revenue The marginal revenue curve for the monopoly firm lies below its demand curve. It shows the additional revenue gained from selling an additional unit. Notice that, as always, marginal values are plotted at the midpoints of the respective intervals. When the demand curve is linear, as in Figure 10.4 "Demand and Marginal Revenue", the marginal revenue curve can be placed according to the following rules: the marginal revenue curve is always below the demand curve and the marginal revenue curve will bisect any horizontal line drawn between the vertical axis and the demand curve. To put it another way, the marginal revenue curve will be twice as steep as the demand curve. The demand curve in Figure 10.4 "Demand and Marginal Revenue" is given by the equation Q = 10 − P , which can be written P = 10 − Q . The marginal revenue curve is given by P = 10 − 2 Q , which is twice as steep as the demand curve. The marginal revenue and demand curves in Figure 10.4 "Demand and Marginal Revenue" follow these rules. The marginal revenue curve lies below the demand curve, and it bisects any horizontal line drawn from the vertical axis to the demand curve. At a price of $6, for example, the quantity demanded is 4. The marginal revenue curve passes through 2 units at this price. At a price of 0, the quantity demanded is 10; the marginal revenue curve passes through 5 units at this point. Just as there is a relationship between the firm’s demand curve and the price elasticity of demand, there is a relationship between its marginal revenue curve and elasticity. Where marginal revenue is positive, demand is price elastic. Where marginal revenue is negative, demand is price inelastic. Where marginal revenue is zero, demand is unit price elastic. When marginal revenue is … then demand is … positive, price elastic. negative, price inelastic. zero, unit price elastic. A firm would not produce an additional unit of output with negative marginal revenue. And, assuming that the production of an additional unit has some cost, a firm would not produce the extra unit if it has zero marginal revenue. Because a monopoly firm will generally operate where marginal revenue is positive, we see once again that it will operate in the elastic range of its demand curve. Monopoly Equilibrium: Applying the Marginal Decision Rule Profit-maximizing behavior is always based on the marginal decision rule: Additional units of a good should be produced as long as the marginal revenue of an additional unit exceeds the marginal cost. The maximizing solution occurs where marginal revenue equals marginal cost. As always, firms seek to maximize economic profit, and costs are measured in the economic sense of opportunity cost. Figure 10.5 "The Monopoly Solution" shows a demand curve and an associated marginal revenue curve facing a monopoly firm. The marginal cost curve is like those we derived earlier; it falls over the range of output in which the firm experiences increasing marginal returns, then rises as the firm experiences diminishing marginal returns. Figure 10.5 The Monopoly Solution The monopoly firm maximizes profit by producing an output Qm at point G, where the marginal revenue and marginal cost curves intersect. It sells this output at price Pm. To determine the profit-maximizing output, we note the quantity at which the firm’s marginal revenue and marginal cost curves intersect ( Qm in Figure 10.5 "The Monopoly Solution" ). We read up from Qm to the demand curve to find the price Pm at which the firm can sell Qm units per period. The profit-maximizing price and output are given by point E on the demand curve. Thus we can determine a monopoly firm’s profit-maximizing price and output by following three steps: Determine the demand, marginal revenue, and marginal cost curves. Select the output level at which the marginal revenue and marginal cost curves intersect. Determine from the demand curve the price at which that output can be sold. Figure 10.6 Computing Monopoly Profit A monopoly firm’s profit per unit is the difference between price and average total cost. Total profit equals profit per unit times the quantity produced. Total profit is given by the area of the shaded rectangle ATCmPm EF. Once we have determined the monopoly firm’s price and output, we can determine its economic profit by adding the firm’s average total cost curve to the graph showing demand, marginal revenue, and marginal cost, as shown in Figure 10.6 "Computing Monopoly Profit". The average total cost ( ATC) at an output of Qm units is ATCm. The firm’s profit per unit is thus Pm - ATCm. Total profit is found by multiplying the firm’s output, Qm, by profit per unit, so total profit equals Qm ( Pm - ATCm )—the area of the shaded rectangle in Figure 10.6 "Computing Monopoly Profit". Heads Up! Dispelling Myths About Monopoly Three common misconceptions about monopoly are: Because there are no rivals selling the products of monopoly firms, they can charge whatever they want. Monopolists will charge whatever the market will bear. Because monopoly firms have the market to themselves, they are guaranteed huge profits. As Figure 10.5 "The Monopoly Solution" shows, once the monopoly firm decides on the number of units of output that will maximize profit, the price at which it can sell that many units is found by “reading off” the demand curve the price associated with that many units. If it tries to sell Qm units of output for more than Pm, some of its output will go unsold. The monopoly firm can set its price, but is restricted to price and output combinations that lie on its demand curve. It cannot just “charge whatever it wants.” And if it charges “all the market will bear,” it will sell either 0 or, at most, 1 unit of output. Neither is the monopoly firm guaranteed a profit. Consider Figure 10.6 "Computing Monopoly Profit". Suppose the average total cost curve, instead of lying below the demand curve for some output levels as shown, were instead everywhere above the demand curve. In that case, the monopoly will incur losses no matter what price it chooses, since average total cost will always be greater than any price it might charge. As is the case for perfect competition, the monopoly firm can keep producing in the short run so long as price exceeds average variable cost. In the long run, it will stay in business only if it can cover all of its costs. Key Takeaways If a firm faces a downward-sloping demand curve, marginal revenue is less than price. Marginal revenue is positive in the elastic range of a demand curve, negative in the inelastic range, and zero where demand is unit price elastic. If a monopoly firm faces a linear demand curve, its marginal revenue curve is also linear, lies below the demand curve, and bisects any horizontal line drawn from the vertical axis to the demand curve. To maximize profit or minimize losses, a monopoly firm produces the quantity at which marginal cost equals marginal revenue. Its price is given by the point on the demand curve that corresponds to this quantity. Try It! The Troll Road Company is considering building a toll road. It estimates that its linear demand curve is as shown below. Assume that the fixed cost of the road is $0.5 million per year. Maintenance costs, which are the only other costs of the road, are also given in the table. Tolls per trip $1.00 0.90 0.80 0.70 0.60 0.50 Number of trips per year (in millions) 1 2 3 4 5 6 Maintenance cost per year (in millions) $0.7 1.2 1.8 2.9 4.2 6.0 Using the midpoint convention, compute the profit-maximizing level of output. Using the midpoint convention, what price will the company charge? What is marginal revenue at the profit-maximizing output level? How does marginal revenue compare to price? Case in Point: Profit-Maximizing Sports Teams © 2010 Jupiterimages Corporation Love of the game? Love of the city? Are those the factors that influence owners of professional sports teams in setting admissions prices? Four economists at the University of Vancouver have what they think is the answer for one group of teams: professional hockey teams set admission prices at levels that maximize their profits. They regard hockey teams as monopoly firms and use the monopoly model to examine the team’s behavior. The economists, Donald G. Ferguson, Kenneth G. Stewart, John Colin H. Jones, and Andre Le Dressay, used data from three seasons to estimate demand and marginal revenue curves facing each team in the National Hockey League. They found that demand for a team’s tickets is affected by population and income in the team’s home city, the team’s standing in the National Hockey League, and the number of superstars on the team. Because a sports team’s costs do not vary significantly with the number of fans who attend a given game, the economists assumed that marginal cost is zero. The profit-maximizing number of seats sold per game is thus the quantity at which marginal revenue is zero, provided a team’s stadium is large enough to hold that quantity of fans. This unconstrained quantity is labeled Qu, with a corresponding price Pu in the graph. Stadium size and the demand curve facing a team might prevent the team from selling the profit-maximizing quantity of tickets. If its stadium holds only Qc fans, for example, the team will sell that many tickets at price Pc; its marginal revenue is positive at that quantity. Economic theory thus predicts that the marginal revenue for teams that consistently sell out their games will be positive, and the marginal revenue for other teams will be zero. The economists’ statistical results were consistent with the theory. They found that teams that do not typically sell out their games operate at a quantity at which marginal revenue is about zero and that teams with sellouts have positive marginal revenue. “It’s clear that these teams are very sophisticated in their use of pricing to maximize profits,” Mr. Ferguson said. Not all studies of sporting event pricing have confirmed this conclusion. While a study of major league baseball ticket pricing by Leo Kahane and Stephen Shmanske and one of baseball spring training game tickets by Michael Donihue, David Findlay, and Peter Newberry suggested that tickets are priced where demand is unit elastic, some other studies of ticket pricing of sporting events have found that tickets are priced in the inelastic region of the demand curve. On its face, this would mean that team owners were not maximizing profits. Why would team owners do this? Are they really charging too little? To fans, it certainly may not seem so! While some have argued that owners want to please fans by selling tickets for less than the profit-maximizing price, others argue they do so for possible political considerations, for example, keeping prices below the profit-maximizing level could help when they are asking for subsidies for building new stadiums. In line with the notion that team owners do behave like other profit-maximizing firms, another line of research, for example, that proposed by Anthony Krautmann and David Berri, has been to recognize that owners also get revenue from selling concessions so that getting more fans at the game may boost revenue from other sources. Sources: Michael R. Donihue, David W. Findlay, and Peter W. Newberry, “An Analysis of Attendance at Major League Baseball Spring Games,” Journal of Sports Economics 8:1 (February 2007): 39–61; Donald G. Ferguson et al., “The Pricing of Sports Events: Do Teams Maximize Profit?” Journal of Industrial Economics 39:3 (March 1991): 297–310 and personal interview; Leo Kahane and Stephen Shmanske, “Team Roster Turnover and Attendance in Major League Baseball,” Applied Economics 29 (1997): 425–431; and Anthony C. Krautmann and David J. Berri, “Can We Find It at the Concessions?” Journal of Sports Economics 8:2 (April 2007): 183–191. Answer to Try It! Problem Maintenance costs constitute the variable costs associated with building the road. In order to answer the first four parts of the question, you will need to compute total revenue, marginal revenue, and marginal cost, as shown at right: Using the “midpoint” convention, the profit-maximizing level of output is 2.5 million trips per year. With that number of trips, marginal revenue ($0.60) equals marginal cost ($0.60). Again, we use the “midpoint” convention. The company will charge a toll of $0.85. The marginal revenue is $0.60, which is less than the $0.85 toll (price).	msmarco_doc_00_11667665
http://2012books.lardbucket.org/books/economics-principles-v2.0/s13-monopoly.html	Monopoly	Chapter 10 Monopoly Chapter 10 Monopoly Start Up: Surrounded by Monopolies 10.1 The Nature of Monopoly Learning Objectives Sources of Monopoly Power Economies of Scale Location Sunk Costs Restricted Ownership of Raw Materials and Inputs Government Restrictions Key Takeaways Try It! Case in Point: The Ambassador Bridge Fights to Maintain Its Monopoly Answers to Try It! Problems 10.2 The Monopoly Model Learning Objectives Monopoly and Market Demand Total Revenue and Price Elasticity Demand and Marginal Revenue Monopoly Equilibrium: Applying the Marginal Decision Rule Heads Up! Key Takeaways Try It! Case in Point: Profit-Maximizing Sports Teams Answer to Try It! Problem 10.3 Assessing Monopoly Learning Objectives Efficiency, Equity, and Concentration of Power Monopoly and Efficiency Monopoly and Equity Monopoly and the Concentration of Power Public Policy Toward Monopoly The Fragility of Monopoly Power Key Takeaways Try It! Case in Point: Technological Change, Public Policy, and Competition in Telecommunications Answers to Try It! Problems	Monopoly Chapter 10 Monopoly Start Up: Surrounded by Monopolies If your college or university is like most, you spend a lot of time, and money, dealing with firms that face very little competition. Your campus bookstore is likely to be the only local firm selling the texts that professors require you to read. Your school may have granted an exclusive franchise to a single firm for food service and to another firm for vending machines. A single firm may provide your utilities—electricity, natural gas, and water. Unlike the individual firms we have previously studied that operate in a competitive market, taking the price, which is determined by demand and supply, as given, in this chapter we investigate the behavior of firms that have their markets all to themselves. As the only suppliers of particular goods or services, they face the downward-sloping market demand curve alone. We will find that firms that have their markets all to themselves behave in a manner that is in many respects quite different from the behavior of firms in perfect competition. Such firms continue to use the marginal decision rule in maximizing profits, but their freedom to select from the price and quantity combinations given by the market demand curve affects the way in which they apply this rule. We will show that a monopoly firm is likely to produce less and charge more for what it produces than firms in a competitive industry. As a result, a monopoly solution is likely to be inefficient from society’s perspective. We will explore the policy alternatives available to government agencies in dealing with monopoly firms. First, though, we will look at characteristics of monopoly and at conditions that give rise to monopolies in the first place. 10.1 The Nature of Monopoly Learning Objectives Define monopoly and the relationship between price setting and monopoly power. List and explain the sources of monopoly power and how they can change over time. Define what is meant by a natural monopoly. Monopoly is at the opposite end of the spectrum of market models from perfect competition. A monopoly A firm that that is the only producer of a good or service for which there are no close substitutes and for which entry by potential rivals is prohibitively difficult. firm has no rivals. It is the only firm in its industry. There are no close substitutes for the good or service a monopoly produces. Not only does a monopoly firm have the market to itself, but it also need not worry about other firms entering. In the case of monopoly, entry by potential rivals is prohibitively difficult. A monopoly does not take the market price as given; it determines its own price. It selects from its demand curve the price that corresponds to the quantity the firm has chosen to produce in order to earn the maximum profit possible. The entry of new firms, which eliminates profit in the long run in a competitive market, cannot occur in the monopoly model. A firm that sets or picks price based on its output decision is called a price setter A firm that sets or picks price based on its output decision. . A firm that acts as a price setter possesses monopoly power The ability to act as a price setter. . We shall see in the next chapter that monopolies are not the only firms that have this power; however, the absence of rivals in monopoly gives it much more price-setting power. As was the case when we discussed perfect competition in the previous chapter, the assumptions of the monopoly model are rather strong. In assuming there is one firm in a market, we assume there are no other firms producing goods or services that could be considered part of the same market as that of the monopoly firm. In assuming blocked entry, we assume, for reasons we will discuss below, that no other firm can enter that market. Such conditions are rare in the real world. As always with models, we make the assumptions that define monopoly in order to simplify our analysis, not to describe the real world. The result is a model that gives us important insights into the nature of the choices of firms and their impact on the economy. Sources of Monopoly Power Why are some markets dominated by single firms? What are the sources of monopoly power? Economists have identified a number of conditions that, individually or in combination, can lead to domination of a market by a single firm and create barriers that prevent the entry of new firms. Barriers to entry Characteristic of a particular market that block the entry of new firms in a monopoly market. are characteristics of a particular market that block new firms from entering it. They include economies of scale, special advantages of location, high sunk costs, a dominant position in the ownership of some of the inputs required to produce the good, and government restrictions. These barriers may be interrelated, making entry that much more formidable. Although these barriers might allow one firm to gain and hold monopoly control over a market, there are often forces at work that can erode this control. Economies of Scale Scale economies and diseconomies define the shape of a firm’s long-run average cost ( LRAC) curve as it increases its output. If long-run average cost declines as the level of production increases, a firm is said to experience economies of scale. A firm that confronts economies of scale over the entire range of outputs demanded in its industry is a natural monopoly A firm that confronts economies of scale over the entire range of outputs demanded in its industry. . Utilities that distribute electricity, water, and natural gas to some markets are examples. In a natural monopoly, the LRAC of any one firm intersects the market demand curve where long-run average costs are falling or are at a minimum. If this is the case, one firm in the industry will expand to exploit the economies of scale available to it. Because this firm will have lower unit costs than its rivals, it can drive them out of the market and gain monopoly control over the industry. Suppose there are 12 firms, each operating at the scale shown by ATC1 (average total cost) in Figure 10.1 "Economies of Scale Lead to Natural Monopoly". A firm that expanded its scale of operation to achieve an average total cost curve such as ATC2 could produce 240 units of output at a lower cost than could the smaller firms producing 20 units each. By cutting its price below the minimum average total cost of the smaller plants, the larger firm could drive the smaller ones out of business. In this situation, the industry demand is not large enough to support more than one firm. If another firm attempted to enter the industry, the natural monopolist would always be able to undersell it. Figure 10.1 Economies of Scale Lead to Natural Monopoly A firm with falling LRAC throughout the range of outputs relevant to existing demand ( D) will monopolize the industry. Here, one firm operating with a large plant ( ATC2) produces 240 units of output at a lower cost than the $7 cost per unit of the 12 firms operating at a smaller scale ( ATC1 ), and producing 20 units of output each. Location Sometimes monopoly power is the result of location. For example, sellers in markets isolated by distance from their nearest rivals have a degree of monopoly power. The local movie theater in a small town has a monopoly in showing first-run movies. Doctors, dentists, and mechanics in isolated towns may also be monopolists. Sunk Costs The greater the cost of establishing a new business in an industry, the more difficult it is to enter that industry. That cost will, in turn, be greater if the outlays required to start a business are unlikely to be recovered if the business should fail. Suppose, for example, that entry into a particular industry requires extensive advertising to make consumers aware of the new brand. Should the effort fail, there is no way to recover the expenditures for such advertising. An expenditure that has already been made and that cannot be recovered is called a sunk cost An expenditure that has already been made and that cannot be recovered. . If a substantial fraction of a firm’s initial outlays will be lost upon exit from the industry, exit will be costly. Difficulty of exit can make for difficulty of entry. The more firms have to lose from an unsuccessful effort to penetrate a particular market, the less likely they are to try. The potential for high sunk costs could thus contribute to the monopoly power of an established firm by making entry by other firms more difficult. Restricted Ownership of Raw Materials and Inputs In very few cases the source of monopoly power is the ownership of strategic inputs. If a particular firm owns all of an input required for the production of a particular good or service, then it could emerge as the only producer of that good or service. The Aluminum Company of America (ALCOA) gained monopoly power through its ownership of virtually all the bauxite mines in the world (bauxite is the source of aluminum). The International Nickel Company of Canada at one time owned virtually all the world’s nickel. De Beers acquired rights to nearly all the world’s diamond production, giving it enormous power in the market for diamonds. With new diamond supplies in Canada, Australia, and Russia being developed and sold independently of DeBeers, however, this power has declined, and today DeBeers controls a substantially smaller percentage of the world’s supply. Government Restrictions Another important basis for monopoly power consists of special privileges granted to some business firms by government agencies. State and local governments have commonly assigned exclusive franchises—rights to conduct business in a specific market—to taxi and bus companies, to cable television companies, and to providers of telephone services, electricity, natural gas, and water, although the trend in recent years has been to encourage competition for many of these services. Governments might also regulate entry into an industry or a profession through licensing and certification requirements. Governments also provide patent protection to inventors of new products or production methods in order to encourage innovation; these patents may afford their holders a degree of monopoly power during the 17-year life of the patent. Patents can take on extra importance when network effects are present. Network effects Situations where products become more useful the larger the number of users of the product. arise in situations where products become more useful the larger the number of users of the product. For example, one advantage of using the Windows computer operating system is that so many other people use it. That has advantages in terms of sharing files and other information. Key Takeaways An industry with a single firm, in which entry is blocked, is called a monopoly. A firm that sets or picks price depending on its output decision is called a price setter. A price setter possesses monopoly power. The sources of monopoly power include economies of scale, locational advantages, high sunk costs associated with entry, restricted ownership of key inputs, and government restrictions, such as exclusive franchises, licensing and certification requirements, and patents. A firm that confronts economies of scale over the entire range of output demanded in an industry is a natural monopoly. Try It! What is the source of monopoly power—if any—in each of the following situations? The U.S. Food and Drug Administration granted Burroughs Wellcome exclusive rights until 2005 to manufacture and distribute AZT, a drug used in the treatment of AIDS. John and Mary Doe run the only shoe repair shop in town. One utility company distributes residential electricity in your town. The widespread use of automatic teller machines (ATMs) has proven a boon to Diebold, the principal manufacturer of the machines. Case in Point: The Ambassador Bridge Fights to Maintain Its Monopoly © 2010 Jupiterimages Corporation Matty Moroun was quietly enjoying his monopoly power. He is the owner of the 80-year-old Ambassador Bridge, a suspension bridge that is the only connection between Detroit, Michigan, and Windsor, Ontario. He purchased the bridge from Warren Buffet in 1974 for $30 million. Forbes estimates that it is now worth more than $500 million. Mr. Moroun oversees the artery over which $100 billion of goods—one-quarter of U.S. trade with Canada and 40% of all truck shipments from the United States—make their way between the two countries. Despite complaints of high and rising tolls—he has more than doubled fares for cars and tripled fares for trucks—Mr. Moroun has so far held on. Kenneth Davies, a lawyer who often battles Mr. Moroun in court, is a grudging admirer. “He’s very intelligent and very aggressive. His avarice and greed are just American capitalism at work,” he told Forbes. What are the sources of his monopoly power? With the closest alternative bridge across the Detroit River two hours away, location is a big plus. In addition, the cost of creating a new transportation link is high. A group that is considering converting an old train tunnel to truck use and boring a new train tunnel some distance away is facing a $600 million price tag for the project. In addition to having entry by potential competitors blocked, he has a status not shared by most other monopolists. The Michigan Supreme Court ruled in 2008 that the city of Detroit cannot regulate his business because of the bridge’s international nature. Canadian courts have barred any effort by Canadian authorities to regulate him. He will not even allow inspectors from the government of the United States to set foot on his bridge. Increased security since 9/11 has caused delays, but Mr. Moroun has eased these by increasing his own spending on security to $50,000 a week and by building additional inspection stations and gifting them to the U.S. inspection agency, the General Services Administration. Even a monopolist understands the importance of keeping his customers content! Mr. Maroun has even proposed building a new bridge just next to the existing bridge. Because of the terrorist attacks on 9/11 and the concern about vulnerability and security, calls to deal with this monopoly have increased. Some people argue that the government should buy what is the most important single international arterial in North America, while others have called for more regulatory oversight. The Canadian and Michigan governments have been discussing the possibility of building a publicly funded bridge nearby. Time will tell whether Mr. Moroun can hold onto what Forbes writers Stephane Fitch and Joann Muller dubbed “the best monopoly you never heard of.” Sources: Stephane Fitch and Joann Muller, “The Troll Under the Bridge,” Forbes 174:10 (November 15, 2004): 134–139; John Gallagher, “Plan Uses Parkway to Ease Ambassador Bridge Traffic,” Detroit Free Press, May 1, 2008; “State Supreme Court Sides With Ambassador Bridge in Dispute,” Detroit News, May 7, 2008; and “A Floating Detroit River Bridge?” The Toronto Star, July 30, 2010. Answers to Try It! Problems The government’s grant of an exclusive franchise to the drug gave the firm monopoly power. While John and Mary have the only shop in town, this is an easy entry business. Further, there may be competitors in the nearby town. John and Mary probably have monopoly power, but they do not have a monopoly. Natural monopoly. Patent with strong network effects. 10.2 The Monopoly Model Learning Objectives Explain the relationship between price and marginal revenue when a firm faces a downward-sloping demand curve. Explain the relationship between marginal revenue and elasticity along a linear demand curve. Apply the marginal decision rule to explain how a monopoly maximizes profit. Analyzing choices is a more complex challenge for a monopoly firm than for a perfectly competitive firm. After all, a competitive firm takes the market price as given and determines its profit-maximizing output. Because a monopoly has its market all to itself, it can determine not only its output but its price as well. What kinds of price and output choices will such a firm make? We will answer that question in the context of the marginal decision rule: a firm will produce additional units of a good until marginal revenue equals marginal cost. To apply that rule to a monopoly firm, we must first investigate the special relationship between demand and marginal revenue for a monopoly. Monopoly and Market Demand Because a monopoly firm has its market all to itself, it faces the market demand curve. Figure 10.2 "Perfect Competition Versus Monopoly" compares the demand situations faced by a monopoly and a perfectly competitive firm. In Panel (a), the equilibrium price for a perfectly competitive firm is determined by the intersection of the demand and supply curves. The market supply curve is found simply by summing the supply curves of individual firms. Those, in turn, consist of the portions of marginal cost curves that lie above the average variable cost curves. The marginal cost curve, MC, for a single firm is illustrated. Notice the break in the horizontal axis indicating that the quantity produced by a single firm is a trivially small fraction of the whole. In the perfectly competitive model, one firm has nothing to do with the determination of the market price. Each firm in a perfectly competitive industry faces a horizontal demand curve defined by the market price. Figure 10.2 Perfect Competition Versus Monopoly Panel (a) shows the determination of equilibrium price and output in a perfectly competitive market. A typical firm with marginal cost curve MC is a price taker, choosing to produce quantity q at the equilibrium price P. In Panel (b) a monopoly faces a downward-sloping market demand curve. As a profit maximizer, it determines its profit-maximizing output. Once it determines that quantity, however, the price at which it can sell that output is found from the demand curve. The monopoly firm can sell additional units only by lowering price. The perfectly competitive firm, by contrast, can sell any quantity it wants at the market price. Contrast the situation shown in Panel (a) with the one faced by the monopoly firm in Panel (b). Because it is the only supplier in the industry, the monopolist faces the downward-sloping market demand curve alone. It may choose to produce any quantity. But, unlike the perfectly competitive firm, which can sell all it wants at the going market price, a monopolist can sell a greater quantity only by cutting its price. Suppose, for example, that a monopoly firm can sell quantity Q1 units at a price P1 in Panel (b). If it wants to increase its output to Q2 units—and sell that quantity—it must reduce its price to P2. To sell quantity Q3 it would have to reduce the price to P3. The monopoly firm may choose its price and output, but it is restricted to a combination of price and output that lies on the demand curve. It could not, for example, charge price P1 and sell quantity Q3. To be a price setter, a firm must face a downward-sloping demand curve. Total Revenue and Price Elasticity A firm’s elasticity of demand with respect to price has important implications for assessing the impact of a price change on total revenue. Also, the price elasticity of demand can be different at different points on a firm’s demand curve. In this section, we shall see why a monopoly firm will always select a price in the elastic region of its demand curve. Suppose the demand curve facing a monopoly firm is given by Equation 10.1, where Q is the quantity demanded per unit of time and P is the price per unit: Equation 10.1 Q = 10 − P This demand equation implies the demand schedule shown in Figure 10.3 "Demand, Elasticity, and Total Revenue". Total revenue for each quantity equals the quantity times the price at which that quantity is demanded. The monopoly firm’s total revenue curve is given in Panel (b). Because a monopolist must cut the price of every unit in order to increase sales, total revenue does not always increase as output rises. In this case, total revenue reaches a maximum of $25 when 5 units are sold. Beyond 5 units, total revenue begins to decline. Figure 10.3 Demand, Elasticity, and Total Revenue Suppose a monopolist faces the downward-sloping demand curve shown in Panel (a). In order to increase the quantity sold, it must cut the price. Total revenue is found by multiplying the price and quantity sold at each price. Total revenue, plotted in Panel (b), is maximized at $25, when the quantity sold is 5 units and the price is $5. At that point on the demand curve, the price elasticity of demand equals −1. The demand curve in Panel (a) of Figure 10.3 "Demand, Elasticity, and Total Revenue" shows ranges of values of the price elasticity of demand. We have learned that price elasticity varies along a linear demand curve in a special way: Demand is price elastic at points in the upper half of the demand curve and price inelastic in the lower half of the demand curve. If demand is price elastic, a price reduction increases total revenue. To sell an additional unit, a monopoly firm must lower its price. The sale of one more unit will increase revenue because the percentage increase in the quantity demanded exceeds the percentage decrease in the price. The elastic range of the demand curve corresponds to the range over which the total revenue curve is rising in Panel (b) of Figure 10.3 "Demand, Elasticity, and Total Revenue". If demand is price inelastic, a price reduction reduces total revenue because the percentage increase in the quantity demanded is less than the percentage decrease in the price. Total revenue falls as the firm sells additional units over the inelastic range of the demand curve. The downward-sloping portion of the total revenue curve in Panel (b) corresponds to the inelastic range of the demand curve. Finally, recall that the midpoint of a linear demand curve is the point at which demand becomes unit price elastic. That point on the total revenue curve in Panel (b) corresponds to the point at which total revenue reaches a maximum. The relationship among price elasticity, demand, and total revenue has an important implication for the selection of the profit-maximizing price and output: A monopoly firm will never choose a price and output in the inelastic range of the demand curve. Suppose, for example, that the monopoly firm represented in Figure 10.3 "Demand, Elasticity, and Total Revenue" is charging $3 and selling 7 units. Its total revenue is thus $21. Because this combination is in the inelastic portion of the demand curve, the firm could increase its total revenue by raising its price. It could, at the same time, reduce its total cost. Raising price means reducing output; a reduction in output would reduce total cost. If the firm is operating in the inelastic range of its demand curve, then it is not maximizing profits. The firm could earn a higher profit by raising price and reducing output. It will continue to raise its price until it is in the elastic portion of its demand curve. A profit-maximizing monopoly firm will therefore select a price and output combination in the elastic range of its demand curve. Of course, the firm could choose a point at which demand is unit price elastic. At that point, total revenue is maximized. But the firm seeks to maximize profit, not total revenue. A solution that maximizes total revenue will not maximize profit unless marginal cost is zero. Demand and Marginal Revenue In the perfectly competitive case, the additional revenue a firm gains from selling an additional unit—its marginal revenue—is equal to the market price. The firm’s demand curve, which is a horizontal line at the market price, is also its marginal revenue curve. But a monopoly firm can sell an additional unit only by lowering the price. That fact complicates the relationship between the monopoly’s demand curve and its marginal revenue. Suppose the firm in Figure 10.3 "Demand, Elasticity, and Total Revenue" sells 2 units at a price of $8 per unit. Its total revenue is $16. Now it wants to sell a third unit and wants to know the marginal revenue of that unit. To sell 3 units rather than 2, the firm must lower its price to $7 per unit. Total revenue rises to $21. The marginal revenue of the third unit is thus $5. But the price at which the firm sells 3 units is $7. Marginal revenue is less than price. To see why the marginal revenue of the third unit is less than its price, we need to examine more carefully how the sale of that unit affects the firm’s revenues. The firm brings in $7 from the sale of the third unit. But selling the third unit required the firm to charge a price of $7 instead of the $8 the firm was charging for 2 units. Now the firm receives less for the first 2 units. The marginal revenue of the third unit is the $7 the firm receives for that unit minus the $1 reduction in revenue for each of the first two units. The marginal revenue of the third unit is thus $5. (In this chapter we assume that the monopoly firm sells all units of output at the same price. In the next chapter, we will look at cases in which firms charge different prices to different customers.) Marginal revenue is less than price for the monopoly firm. Figure 10.4 "Demand and Marginal Revenue" shows the relationship between demand and marginal revenue, based on the demand curve introduced in Figure 10.3 "Demand, Elasticity, and Total Revenue". As always, we follow the convention of plotting marginal values at the midpoints of the intervals. Figure 10.4 Demand and Marginal Revenue The marginal revenue curve for the monopoly firm lies below its demand curve. It shows the additional revenue gained from selling an additional unit. Notice that, as always, marginal values are plotted at the midpoints of the respective intervals. When the demand curve is linear, as in Figure 10.4 "Demand and Marginal Revenue", the marginal revenue curve can be placed according to the following rules: the marginal revenue curve is always below the demand curve and the marginal revenue curve will bisect any horizontal line drawn between the vertical axis and the demand curve. To put it another way, the marginal revenue curve will be twice as steep as the demand curve. The demand curve in Figure 10.4 "Demand and Marginal Revenue" is given by the equation Q = 10 − P , which can be written P = 10 − Q . The marginal revenue curve is given by P = 10 − 2 Q , which is twice as steep as the demand curve. The marginal revenue and demand curves in Figure 10.4 "Demand and Marginal Revenue" follow these rules. The marginal revenue curve lies below the demand curve, and it bisects any horizontal line drawn from the vertical axis to the demand curve. At a price of $6, for example, the quantity demanded is 4. The marginal revenue curve passes through 2 units at this price. At a price of 0, the quantity demanded is 10; the marginal revenue curve passes through 5 units at this point. Just as there is a relationship between the firm’s demand curve and the price elasticity of demand, there is a relationship between its marginal revenue curve and elasticity. Where marginal revenue is positive, demand is price elastic. Where marginal revenue is negative, demand is price inelastic. Where marginal revenue is zero, demand is unit price elastic. When marginal revenue is … then demand is … positive, price elastic. negative, price inelastic. zero, unit price elastic. A firm would not produce an additional unit of output with negative marginal revenue. And, assuming that the production of an additional unit has some cost, a firm would not produce the extra unit if it has zero marginal revenue. Because a monopoly firm will generally operate where marginal revenue is positive, we see once again that it will operate in the elastic range of its demand curve. Monopoly Equilibrium: Applying the Marginal Decision Rule Profit-maximizing behavior is always based on the marginal decision rule: Additional units of a good should be produced as long as the marginal revenue of an additional unit exceeds the marginal cost. The maximizing solution occurs where marginal revenue equals marginal cost. As always, firms seek to maximize economic profit, and costs are measured in the economic sense of opportunity cost. Figure 10.5 "The Monopoly Solution" shows a demand curve and an associated marginal revenue curve facing a monopoly firm. The marginal cost curve is like those we derived earlier; it falls over the range of output in which the firm experiences increasing marginal returns, then rises as the firm experiences diminishing marginal returns. Figure 10.5 The Monopoly Solution The monopoly firm maximizes profit by producing an output Qm at point G, where the marginal revenue and marginal cost curves intersect. It sells this output at price Pm. To determine the profit-maximizing output, we note the quantity at which the firm’s marginal revenue and marginal cost curves intersect ( Qm in Figure 10.5 "The Monopoly Solution" ). We read up from Qm to the demand curve to find the price Pm at which the firm can sell Qm units per period. The profit-maximizing price and output are given by point E on the demand curve. Thus we can determine a monopoly firm’s profit-maximizing price and output by following three steps: Determine the demand, marginal revenue, and marginal cost curves. Select the output level at which the marginal revenue and marginal cost curves intersect. Determine from the demand curve the price at which that output can be sold. Figure 10.6 Computing Monopoly Profit A monopoly firm’s profit per unit is the difference between price and average total cost. Total profit equals profit per unit times the quantity produced. Total profit is given by the area of the shaded rectangle ATCmPm EF. Once we have determined the monopoly firm’s price and output, we can determine its economic profit by adding the firm’s average total cost curve to the graph showing demand, marginal revenue, and marginal cost, as shown in Figure 10.6 "Computing Monopoly Profit". The average total cost ( ATC) at an output of Qm units is ATCm. The firm’s profit per unit is thus Pm - ATCm. Total profit is found by multiplying the firm’s output, Qm, by profit per unit, so total profit equals Qm ( Pm - ATCm )—the area of the shaded rectangle in Figure 10.6 "Computing Monopoly Profit". Heads Up! Dispelling Myths About Monopoly Three common misconceptions about monopoly are: Because there are no rivals selling the products of monopoly firms, they can charge whatever they want. Monopolists will charge whatever the market will bear. Because monopoly firms have the market to themselves, they are guaranteed huge profits. As Figure 10.5 "The Monopoly Solution" shows, once the monopoly firm decides on the number of units of output that will maximize profit, the price at which it can sell that many units is found by “reading off” the demand curve the price associated with that many units. If it tries to sell Qm units of output for more than Pm, some of its output will go unsold. The monopoly firm can set its price, but is restricted to price and output combinations that lie on its demand curve. It cannot just “charge whatever it wants.” And if it charges “all the market will bear,” it will sell either 0 or, at most, 1 unit of output. Neither is the monopoly firm guaranteed a profit. Consider Figure 10.6 "Computing Monopoly Profit". Suppose the average total cost curve, instead of lying below the demand curve for some output levels as shown, were instead everywhere above the demand curve. In that case, the monopoly will incur losses no matter what price it chooses, since average total cost will always be greater than any price it might charge. As is the case for perfect competition, the monopoly firm can keep producing in the short run so long as price exceeds average variable cost. In the long run, it will stay in business only if it can cover all of its costs. Key Takeaways If a firm faces a downward-sloping demand curve, marginal revenue is less than price. Marginal revenue is positive in the elastic range of a demand curve, negative in the inelastic range, and zero where demand is unit price elastic. If a monopoly firm faces a linear demand curve, its marginal revenue curve is also linear, lies below the demand curve, and bisects any horizontal line drawn from the vertical axis to the demand curve. To maximize profit or minimize losses, a monopoly firm produces the quantity at which marginal cost equals marginal revenue. Its price is given by the point on the demand curve that corresponds to this quantity. Try It! The Troll Road Company is considering building a toll road. It estimates that its linear demand curve is as shown below. Assume that the fixed cost of the road is $0.5 million per year. Maintenance costs, which are the only other costs of the road, are also given in the table. Tolls per trip $1.00 0.90 0.80 0.70 0.60 0.50 Number of trips per year (in millions) 1 2 3 4 5 6 Maintenance cost per year (in millions) $0.7 1.2 1.8 2.9 4.2 6.0 Using the midpoint convention, compute the profit-maximizing level of output. Using the midpoint convention, what price will the company charge? What is marginal revenue at the profit-maximizing output level? How does marginal revenue compare to price? Case in Point: Profit-Maximizing Sports Teams © 2010 Jupiterimages Corporation Love of the game? Love of the city? Are those the factors that influence owners of professional sports teams in setting admissions prices? Four economists at the University of Vancouver have what they think is the answer for one group of teams: professional hockey teams set admission prices at levels that maximize their profits. They regard hockey teams as monopoly firms and use the monopoly model to examine the team’s behavior. The economists, Donald G. Ferguson, Kenneth G. Stewart, John Colin H. Jones, and Andre Le Dressay, used data from three seasons to estimate demand and marginal revenue curves facing each team in the National Hockey League. They found that demand for a team’s tickets is affected by population and income in the team’s home city, the team’s standing in the National Hockey League, and the number of superstars on the team. Because a sports team’s costs do not vary significantly with the number of fans who attend a given game, the economists assumed that marginal cost is zero. The profit-maximizing number of seats sold per game is thus the quantity at which marginal revenue is zero, provided a team’s stadium is large enough to hold that quantity of fans. This unconstrained quantity is labeled Qu, with a corresponding price Pu in the graph. Stadium size and the demand curve facing a team might prevent the team from selling the profit-maximizing quantity of tickets. If its stadium holds only Qc fans, for example, the team will sell that many tickets at price Pc; its marginal revenue is positive at that quantity. Economic theory thus predicts that the marginal revenue for teams that consistently sell out their games will be positive, and the marginal revenue for other teams will be zero. The economists’ statistical results were consistent with the theory. They found that teams that do not typically sell out their games operate at a quantity at which marginal revenue is about zero and that teams with sellouts have positive marginal revenue. “It’s clear that these teams are very sophisticated in their use of pricing to maximize profits,” Mr. Ferguson said. Not all studies of sporting event pricing have confirmed this conclusion. While a study of major league baseball ticket pricing by Leo Kahane and Stephen Shmanske and one of baseball spring training game tickets by Michael Donihue, David Findlay, and Peter Newberry suggested that tickets are priced where demand is unit elastic, some other studies of ticket pricing of sporting events have found that tickets are priced in the inelastic region of the demand curve. On its face, this would mean that team owners were not maximizing profits. Why would team owners do this? Are they really charging too little? To fans, it certainly may not seem so! While some have argued that owners want to please fans by selling tickets for less than the profit-maximizing price, others argue they do so for possible political considerations, for example, keeping prices below the profit-maximizing level could help when they are asking for subsidies for building new stadiums. In line with the notion that team owners do behave like other profit-maximizing firms, another line of research, for example, that proposed by Anthony Krautmann and David Berri, has been to recognize that owners also get revenue from selling concessions so that getting more fans at the game may boost revenue from other sources. Sources: Michael R. Donihue, David W. Findlay, and Peter W. Newberry, “An Analysis of Attendance at Major League Baseball Spring Games,” Journal of Sports Economics 8:1 (February 2007): 39–61; Donald G. Ferguson et al., “The Pricing of Sports Events: Do Teams Maximize Profit?” Journal of Industrial Economics 39:3 (March 1991): 297–310 and personal interview; Leo Kahane and Stephen Shmanske, “Team Roster Turnover and Attendance in Major League Baseball,” Applied Economics 29 (1997): 425–431; and Anthony C. Krautmann and David J. Berri, “Can We Find It at the Concessions?” Journal of Sports Economics 8:2 (April 2007): 183–191. Answer to Try It! Problem Maintenance costs constitute the variable costs associated with building the road. In order to answer the first four parts of the question, you will need to compute total revenue, marginal revenue, and marginal cost, as shown at right: Using the “midpoint” convention, the profit-maximizing level of output is 2.5 million trips per year. With that number of trips, marginal revenue ($0.60) equals marginal cost ($0.60). Again, we use the “midpoint” convention. The company will charge a toll of $0.85. The marginal revenue is $0.60, which is less than the $0.85 toll (price). 10.3 Assessing Monopoly Learning Objectives Explain and illustrate that a monopoly firm produces an output that is less than the efficient level and why this results in a deadweight loss to society. Explain and illustrate how the higher price that a monopoly charges, compared to an otherwise identical perfectly competitive firm, transfers part of consumer surplus to the monopolist and raises questions of equity. Considering both advantages and disadvantages, discuss the potential effects that a monopoly may have on consumer choices, price, quality of products, and technological innovations. Discuss the public policy responses to monopoly. We have seen that for monopolies pursuing profit maximization, the outcome differs from the case of perfect competition. Does this matter to society? In this section, we will focus on the differences that stem from market structure and assess their implications. Efficiency, Equity, and Concentration of Power A monopoly firm determines its output by setting marginal cost equal to marginal revenue. It then charges the price at which it can sell that output, a price determined by the demand curve. That price exceeds marginal revenue; it therefore exceeds marginal cost as well. That contrasts with the case in perfect competition, in which price and marginal cost are equal. The higher price charged by a monopoly firm may allow it a profit—in large part at the expense of consumers, whose reduced options may give them little say in the matter. The monopoly solution thus raises problems of efficiency, equity, and the concentration of power. Monopoly and Efficiency The fact that price in monopoly exceeds marginal cost suggests that the monopoly solution violates the basic condition for economic efficiency, that the price system must confront decision makers with all of the costs and all of the benefits of their choices. Efficiency requires that consumers confront prices that equal marginal costs. Because a monopoly firm charges a price greater than marginal cost, consumers will consume less of the monopoly’s good or service than is economically efficient. To contrast the efficiency of the perfectly competitive outcome with the inefficiency of the monopoly outcome, imagine a perfectly competitive industry whose solution is depicted in Figure 10.7 "Perfect Competition, Monopoly, and Efficiency". The short-run industry supply curve is the summation of individual marginal cost curves; it may be regarded as the marginal cost curve for the industry. A perfectly competitive industry achieves equilibrium at point C, at price Pc and quantity Qc. Figure 10.7 Perfect Competition, Monopoly, and Efficiency Given market demand and marginal revenue, we can compare the behavior of a monopoly to that of a perfectly competitive industry. The marginal cost curve may be thought of as the supply curve of a perfectly competitive industry. The perfectly competitive industry produces quantity Qc and sells the output at price Pc. The monopolist restricts output to Qm and raises the price to Pm. Reorganizing a perfectly competitive industry as a monopoly results in a deadweight loss to society given by the shaded area GRC. It also transfers a portion of the consumer surplus earned in the competitive case to the monopoly firm. Now, suppose that all the firms in the industry merge and a government restriction prohibits entry by any new firms. Our perfectly competitive industry is now a monopoly. Assume the monopoly continues to have the same marginal cost and demand curves that the competitive industry did. The monopoly firm faces the same market demand curve, from which it derives its marginal revenue curve. It maximizes profit at output Qm and charges price Pm. Output is lower and price higher than in the competitive solution. Society would gain by moving from the monopoly solution at Qm to the competitive solution at Qc. The benefit to consumers would be given by the area under the demand curve between Qm and Qc; it is the area Qm RC Qc. An increase in output, of course, has a cost. Because the marginal cost curve measures the cost of each additional unit, we can think of the area under the marginal cost curve over some range of output as measuring the total cost of that output. Thus, the total cost of increasing output from Qm to Qc is the area under the marginal cost curve over that range—the area Qm GC Qc. Subtracting this cost from the benefit gives us the net gain of moving from the monopoly to the competitive solution; it is the shaded area GRC. That is the potential gain from moving to the efficient solution. The area GRC is a deadweight loss. Monopoly and Equity The monopoly solution raises issues not just of efficiency but also of equity. Figure 10.7 "Perfect Competition, Monopoly, and Efficiency" shows that the monopolist charges price Pm rather than the competitive price Pc; the higher price charged by the monopoly firm reduces consumer surplus. Consumer surplus is the difference between what consumers are willing to pay for a good and what they actually pay. It is measured by the area under the demand curve and above the price of the good over the range of output produced. If the industry were competitive, consumer surplus would be the area below the demand curve and above Pc C. With monopoly, consumer surplus would be the area below the demand curve and above Pm R. Part of the reduction in consumer surplus is the area under the demand curve between Qc and Qm; it is contained in the deadweight loss area GRC. But consumers also lose the area of the rectangle bounded by the competitive and monopoly prices and by the monopoly output; this lost consumer surplus is transferred to the monopolist. The fact that society suffers a deadweight loss due to monopoly is an efficiency problem. But the transfer of a portion of consumer surplus to the monopolist is an equity issue. Is such a transfer legitimate? After all, the monopoly firm enjoys a privileged position, protected by barriers to entry from competition. Should it be allowed to extract these gains from consumers? We will see that public policy suggests that the answer is no. Regulatory efforts imposed in monopoly cases often seek to reduce the degree to which monopoly firms extract consumer surplus from consumers by reducing the prices these firms charge. Monopoly and the Concentration of Power The objections to monopoly run much deeper than worries over economic efficiency and high prices. Because it enjoys barriers that block potential rivals, a monopoly firm wields considerable market power. For many people, that concentration of power is objectionable. A decentralized, competitive market constantly tests the ability of firms to satisfy consumers, pushes them to find new products and new and better production methods, and whittles away economic profits. Firms that operate in the shelter of monopoly may be largely immune to such pressures. Consumers are likely to be left with fewer choices, higher costs, and lower quality. Perhaps more important in the view of many economists is the fact that the existence of economic profits provides both an incentive and the means for monopolists to aggressively protect their position and extend it if possible. These economists point out that monopolists may be willing to spend their economic profits in attempts to influence political leaders and public authorities (including regulatory authorities) who can help them maintain or enhance their monopoly position. Graft and corruption may be the result, claim these critics. Indeed, Microsoft has been accused by its rivals of bullying computer manufacturers into installing its web browser, Internet Explorer, exclusively on their computers. Attitudes about Microsoft reflect these concerns. Even among people who feel that its products are good and fairly priced, there is uneasiness about our seeming dependence on them. And once it has secured its dominant position, will it charge more for its products? Will it continue to innovate? Public Policy Toward Monopoly Pulling together what we have learned in this chapter on monopoly and previously on perfect competition, Table 10.1 "Characteristics of Perfect Competition and Monopoly" summarizes the differences between the models of perfect competition and monopoly. Most importantly we note that whereas the perfectly competitive firm is a price taker, the monopoly firm is a price setter. Because of this difference, we can object to monopoly on grounds of economic efficiency; monopolies produce too little and charge too much. Also, the high price and persistent profits strike many as inequitable. Others may simply see monopoly as an unacceptable concentration of power. Table 10.1 Characteristics of Perfect Competition and Monopoly Characteristic or Event Perfect Competition Monopoly Market Large number of sellers and buyers producing a homogeneous good or service, easy entry. Large number of buyers, one seller. Entry is blocked. Demand and marginal revenue curves The firm’s demand and marginal revenue curve is a horizontal line at the market price. The firm faces the market demand curve; marginal revenue is below market demand. Price Determined by demand and supply; each firm is a price taker. Price equals marginal cost. The monopoly firm determines price; it is a price setter. Price is greater than marginal cost. Profit maximization Firms produce where marginal cost equals marginal revenue Firms produce where marginal cost equals marginal revenue and charge the corresponding price on the demand curve. Profit Entry forces economic profit to zero in the long run. Because entry is blocked, a monopoly firm can sustain an economic profit in the long run. Efficiency The equilibrium solution is efficient because price equals marginal cost. The equilibrium solution is inefficient because price is greater than marginal cost. Public policy toward monopoly generally recognizes two important dimensions of the monopoly problem. On the one hand, the combining of competing firms into a monopoly creates an inefficient and, to many, inequitable solution. On the other hand, some industries are characterized as natural monopolies; production by a single firm allows economies of scale that result in lower costs. The combining of competing firms into a monopoly firm or unfairly driving competitors out of business is generally forbidden in the United States. Regulatory efforts to prevent monopoly fall under the purview of the nation’s antitrust laws, discussed in more detail in a later chapter. At the same time, we must be careful to avoid the mistake of simply assuming that competition is the alternative to monopoly, that every monopoly can and should be replaced by a competitive market. One key source of monopoly power, after all, is economies of scale. In the case of natural monopoly, the alternative to a single firm is many small, high-cost producers. We may not like having only one local provider of water, but we might like even less having dozens of providers whose costs—and prices—are higher. Where monopolies exist because economies of scale prevail over the entire range of market demand, they may serve a useful economic role. We might want to regulate their production and pricing choices, but we may not want to give up their cost advantages. Where a natural monopoly exists, the price charged by the firm and other aspects of its behavior may be subject to regulation. Water or natural gas, for example, are often distributed by a public utility—a monopoly firm—at prices regulated by a state or local government agency. Typically, such agencies seek to force the firm to charge lower prices, and to make less profit, than it would otherwise seek. Although economists are hesitant to levy blanket condemnations of monopoly, they are generally sharply critical of monopoly power where no rationale for it exists. When firms have substantial monopoly power only as the result of government policies that block entry, there may be little defense for their monopoly positions. Public policy toward monopoly aims generally to strike the balance implied by economic analysis. Where rationales exist, as in the case of natural monopoly, monopolies are permitted—and their prices are regulated. In other cases, monopoly is prohibited outright. Societies are likely to at least consider taking action of some kind against monopolies unless they appear to offer cost or other technological advantages. The Fragility of Monopoly Power An important factor in thinking about public policy toward monopoly is to recognize that monopoly power can be a fleeting thing. Firms constantly seek out the market power that monopoly offers. When conditions are right to achieve this power, firms that succeed in carving out monopoly positions enjoy substantial profits. But the potential for high profits invites continuing attempts to break down the barriers to entry that insulate monopolies from competition. Technological change and the pursuit of profits chip away constantly at the entrenched power of monopolies. Breathtaking technological change has occurred in the telecommunications industry. Catalog companies are challenging the monopoly positions of some retailers; internet booksellers and online textbook companies such as Flatworldknowledge.com are challenging the monopoly power of your university’s bookstore; and Federal Express, UPS, and other companies are taking on the U.S. Postal Service. The assaults on monopoly power are continuous. Thus, even the monopoly firm must be on the lookout for potential competitors. Potential rivals are always beating at the door and thereby making the monopoly’s fragile market contestable—that is, open to entry, at least in the sense of rival firms producing “close enough,” if not perfect, substitutes—close enough that they might eliminate the firm’s monopoly power. Key Takeaways A monopoly firm produces an output that is less than the efficient level. The result is a deadweight loss to society, given by the area between the demand and marginal cost curves over the range of output between the output chosen by the monopoly firm and the efficient output. The higher price charged by the monopoly firm compared to the perfectly competitive firm reduces consumer surplus, part of which is transferred to the monopolist. This transfer generates an equity issue. The monopoly firm’s market power reduces consumers’ choices and may result in higher prices, but there may be advantages to monopoly as well, such as economies of scale and technological innovations encouraged by the patent system. Public policy toward monopoly consists of antitrust laws and regulation of natural monopolies. Forces that limit the power of monopoly firms are the constant effort by other firms to capture some of the monopoly firm’s profits and technological change that erodes monopoly power. Try It! Does the statement below better describe a firm operating in a perfectly competitive market or a firm that is a monopoly? The demand curve faced by the firm is downward-sloping. The demand curve and the marginal revenue curves are the same. Entry and exit are relatively difficult. The firm is likely to be concerned about antitrust laws. Consumer surplus would be increased if the firm produced more output. Case in Point: Technological Change, Public Policy, and Competition in Telecommunications © 2010 Jupiterimages Corporation Back in the olden days—before 1984—to use a telephone in the United States almost certainly meant being a customer of AT&T. Ma Bell, as the company was known, provided local and long-distance service to virtually every U.S. household. AT&T was clearly a monopoly. The Justice Department began its battle with AT&T in the 1970s, charging it with monopolizing the industry. The case culminated in a landmark 1984 ruling that broke the company up into seven so-called “Baby Bells” that would provide local telephone service. AT&T would continue to provide long-distance service. In effect, the ruling replaced a single national monopoly with seven regional monopolies in local telephone service. AT&T maintained its monopoly position in long-distance service—for a while. The turmoil that has followed illustrates the fragility of monopoly power. Technological developments in the industry have brought dramatic changes. Companies found ways to challenge AT&T’s monopoly position in long-distance telephone service. Cable operators sprang up, typically developing monopoly power over the provision of cable television in their regional markets, but also offering phone service. Mobile phone service, provided by AT&T, and others such as Verizon and Sprint, has led many consumers to do without land-line phone service entirely. Companies that had traditionally been telephone companies have begun providing cable services as well as Internet access. The ready availability of video services on the Internet threatens to make cable providers outmoded middlemen. What is the status of AT&T today? While no longer a monopoly, it is a major player in all of the areas related to telecommunications and larger than all of its competitors in the United States. In 2011, it began the process of buying T-Mobile USA, a mobile service provider focused on the youth market. By the end of that year, however, in the face of strong opposition from the Department of Justice and the Federal Communications Commission on the grounds that the merger would stifle competition in the industry, AT&T announced that it was dropping the deal. Does AT&T have market power today? Undoubtedly. Is it a monopoly? Not anymore. Source: Company Monitor, USA Telecommunication Report, Q2 2011: 69–79. Answers to Try It! Problems monopoly perfect competition monopoly monopoly monopoly	msmarco_doc_00_11691357
http://2012books.lardbucket.org/books/individual-finance/s09-04-budget-variances.html	Budget Variances	5.4 Budget Variances 5.4 Budget Variances Learning Objectives Key Takeaways Exercise	Budget Variances 5.4 Budget Variances Learning Objectives Define and discuss the uses of budget variances. Identify the importance of budget-monitoring activities. Analyze budget variances to understand their causes, including possible changes in micro or macro factors. Analyze budget variances to see potential remedies and to gauge their feasibility. A budget variance A difference between the actual results of your financial activity and your expected, budgeted results. occurs when the actual results of your financial activity differ from your budgeted projections. Since your expectations were based on knowledge from your financial history, micro- and macroeconomic factors, and new information, if there is a variance, it is because your estimate was inaccurate or because one or more of those factors changed unexpectedly. If your estimate was inaccurate—perhaps you had overlooked or ignored a factor—knowing that can help you improve. If one or more of those factors has changed unexpectedly, then identifying the cause of the variance creates new information with which to better assess your situation. At the very least, variances will alert you to the need for adjustments to your budget and to the appropriate choices. Once you have created a budget, your financial life continues. As actual data replace projections, you must monitor the budget compared to your actual activities so that you will notice any serious variances or deviations from the expected outcomes detailed in the budget. Your analysis and understanding of variances constitute new information for adjusting your current behavior, preparing the next budget, or perhaps realistically reassessing your behavior or original goals. The sooner you notice a budget variance, the sooner you can analyze it and, if necessary, adjust for it. The sooner you correct the variance, the less it costs. For example, perhaps you have had a little trouble living within your means, so you have created a budget to help you do so. You have worked out a plan so that total expenses are just as much as total income. In your original budget you expected to have a certain expense for putting gas in your car, which you figured by knowing the mileage that you drive and the current price of gas. You are following your budget and going along just fine. Suddenly, the price of gas goes way up. So does your monthly expense. That means you’ll have to spend less for other expenses in order to keep your total expenses within your budget, lower your gas expense by driving less, and/or increase your income to accommodate this larger expense. Figure 5.14 © 2010 Jupiterimages Corporation In the short term, monitoring your gas expense alerts you to a need to change your financial behavior by driving less, spending less on other things, or earning more. In the long run, if you find this increased expense intolerable, you will make other choices as well to avoid it. Perhaps you would buy a more fuel-efficient car, for example, or change your lifestyle to necessitate less driving. The number and feasibility of your choices will depend on your elasticity of demand for that particular budget item. But if you hadn’t been paying attention, if you had not been monitoring your budget against the real outcomes that were happening as they were happening, you would not have been aware that any change was needed, and you would have found yourself with a surprising budget deficit. It bears repeating that once you have discovered a significant budget variance, you need to analyze what caused it so that you can address it properly. Income results from the sale of labor (wages) or liquidity (interest or dividends). If income deviates from its projection, it is because a different quantity of labor or liquidity was sold at the expected price (e.g., you had fewer house painting contracts than usual but kept your rates the same), the expected quantity of labor or liquidity was sold at a different price (e.g., you had the usual number of contracts but earned less from them), or a different quantity of labor or liquidity was sold at a different price (e.g., you had fewer contracts and charged less to be more competitive). Expenses result from consuming goods or services at a price. If an expense deviates from its projected outcome, it is because a different quantity was consumed at the expected price (e.g., you did not use as much gas), the expected quantity was consumed at a different price (e.g., you used as much gas but the price of gas fell), or a different quantity was consumed at a different price (e.g., you used less gas and bought it for less). Isolating the cause of a variance is useful because different causes will dictate different remedies or opportunities. For example, if your gas expense has increased, is it because you are driving more miles or because the price of gas has gone up? You can’t control the price of gas, but you can control the miles you drive. Isolating the cause allows you to identify realistic choices. In this case, if the variance is too costly, you will need to address it by somehow driving fewer miles. If your income falls, is it because your hourly wage has fallen or because you are working fewer hours? If your wage has fallen, you need to try to increase it either by negotiating with your employer or by seeking a new job at a higher wage. Your success will depend on demand in the labor market and on your usefulness as a supplier of labor. If you are working fewer hours, it may be because your employer is offering you less work or because you choose to work less. If the problem is with your employer, you may need to renegotiate your position or find a new one. However, if your employer is buying less labor because of decreased demand in the labor market, that may be due to an industry or economic cycle, which may affect your success in making that change. If it is your choice of hours that has caused the variance, perhaps that is due to personal factors—you are aging or your dependents require more care and attention—that need to be resolved to allow you to work more. Or perhaps you could simply choose to work more. Identifying why you are going astray from your budget is critical in identifying remedies and choices. Putting those causes in the context of the micro- and macroeconomic factors that affect your situation will make your feasible choices clearer. Figure 5.15 "The Causes of a Budget Variance" shows how these factors can combine to cause a variance. Figure 5.15 The Causes of a Budget Variance After three months, Mark decides to look at his budget variances to make sure he’s on track. His actual results for January–March 2010 are detailed in Figure 5.16 "Mark’s Actual Income and Expenditures, January–March 2010". Figure 5.16 Mark’s Actual Income and Expenditures, January–March 2010 How will Mark analyze the budget variances he finds? In Mark’s case, the income variances are positive. He has picked up a couple of tutoring clients who have committed to lessons through the end of the school year in June; this new information can be used to adjust income. His memorabilia business has done well; the volume of sales has not increased, but the memorabilia market seems to be up and prices are better than expected. The memorabilia business is cyclical; economic expansion and increases in disposable incomes enhance that market. Given the volatility of prices in that market, however, and the fact that there has been no increase in the volume of sales (Mark is not doing more business, just more lucrative business), Mark will not make any adjustments going forward. Interest rates have risen; Mark can use that macroeconomic news to adjust his expected interest income. His expenses are as expected. The only variance is the result of Mark’s decision to cut his travel and entertainment budget for this year (i.e., giving up his vacation) to offset the costs of the roof. He is planning that capital expenditure for October, which (as seen in Figure 5.12 "Mark’s Alternative Cash Budget") will actually make it cheaper to do. His adjusted cash budget is shown in Figure 5.17 "Mark’s Adjusted Cash Budget for 2010". Figure 5.17 Mark’s Adjusted Cash Budget for 2010 With these adjustments, it turns out that Mark can avoid new debt and still support the capital expenditure of the new roof. The increased income that Mark can expect and his decreased expenses (if he can maintain his resolve) can finance the project and still leave him with a bit of savings in his money market account. This situation bears continued monitoring, however. Some improvements are attributable to Mark’s efforts (cutting back on entertainment expenses, giving up his vacation, cultivating new tutoring clients). But Mark has also benefited from macroeconomic factors that have changed to his advantage (rising interest rates, rising memorabilia prices), and those factors could change again to his disadvantage. He has tried to be conservative about making adjustments going forward, but he should continue to keep a close eye on the situation, especially as he gets closer to making the relatively large capital expenditure in October. Sometimes a variance cannot be “corrected” or is due to a micro- or macroeconomic factor beyond your control. In that case, you must adjust your expectations to reality. You may need to adjust expected outcomes or even your ultimate goals. Variances are also measures of the accuracy of your projections; what you learn from them can improve your estimates and your budgeting ability. The unexpected can always occur, but the better you can anticipate what to expect, the more accurate—and useful—your budget process can be. Key Takeaways Recognizing and analyzing variances between actual results and budget expectations identifies potential problems, identifies potential remedies. The more frequently the budget is monitored, generally the sooner adjustments may be made, the less costly adjustments are to make. Budget variances for incomes and expenses should be analyzed to see if they are caused by a difference in actual quantity, actual price, both actual quantity and actual price. Variances also need to be analyzed in the context of micro and macro factors that may change. Exercise You are working fewer hours, which is reducing your income from employment and causing a budget variance. If the choice is yours, what are some microeconomic factors that could be causing this outcome? If the choice is your employer’s, what are some macroeconomic factors that could be sources of the variance? What are your choices for increasing income? Alternatively, what might you change in your financial behavior, budget, or goals to your improve outcomes?	msmarco_doc_00_11749584
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s05-06-arrangements-of-electrons.html	Arrangements of Electrons	2.6 Arrangements of Electrons 2.6 Arrangements of Electrons Learning Objective Example 7 Skill-Building Exercise Example 8 Skill-Building Exercise Answers Key Takeaway Exercises Answers	Arrangements of Electrons 2.6 Arrangements of Electrons Learning Objective Describe how electrons are grouped within atoms. Although we have discussed the general arrangement of subatomic particles in atoms, we have said little about how electrons occupy the space about the nucleus. Do they move around the nucleus at random, or do they exist in some ordered arrangement? The modern theory of electron behavior is called quantum mechanics The modern theory of electron behavior. . It makes the following statements about electrons in atoms: Electrons in atoms can have only certain specific energies. We say that the energies of the electrons are quantized Having a fixed value. . Electrons are organized according to their energies into sets called shells A grouping of electrons within an atom. . Generally the higher the energy of a shell, the farther it is (on average) from the nucleus. Shells do not have specific, fixed distances from the nucleus, but an electron in a higher-energy shell will spend more time farther from the nucleus than does an electron in a lower-energy shell. Shells are further divided into subsets of electrons called subshells A grouping of electrons within a shell. . The first shell has only one subshell, the second shell has two subshells, the third shell has three subshells, and so on. The subshells of each shell are labeled, in order, with the letters s, p, d, and f. Thus, the first shell has only an s subshell, the second shell has an s and a p subshell, the third shell has s, p, and d subshells, and so forth. Different subshells hold a different maximum number of electrons. Any s subshell can hold up to 2 electrons; p, 6; d, 10; and f, 14. It is the arrangement of electrons into shells and subshells that most concerns us here, so we will focus on that. We use numbers to indicate which shell an electron is in. The first shell, closest to the nucleus and with the lowest-energy electrons, is shell 1. This first shell has only one subshell, which is labeled s and can hold a maximum of 2 electrons. We combine the shell and subshell labels when referring to the organization of electrons about a nucleus and use a superscript to indicate how many electrons are in a subshell. Thus, because a hydrogen atom has its single electron in the s subshell of the first shell, we use 1 s1 to describe the electronic structure of hydrogen. This structure is called an electron configuration A shorthand description of the arrangement of electrons in an atom. . Electron configurations are shorthand descriptions of the arrangements of electrons in atoms. The electron configuration of a hydrogen atom is spoken out loud as “one-ess-one.” Helium atoms have 2 electrons. Both electrons fit into the 1 s subshell because s subshells can hold up to 2 electrons; therefore, the electron configuration for helium atoms is 1 s2 (spoken as “one-ess-two”). The 1 s subshell cannot hold 3 electrons (because an s subshell can hold a maximum of 2 electrons), so the electron configuration for a lithium atom cannot be 1 s3. Two of the lithium electrons can fit into the 1 s subshell, but the third electron must go into the second shell. The second shell has two subshells, s and p, which fill with electrons in that order. The 2 s subshell holds a maximum of 2 electrons, and the 2 p subshell holds a maximum of 6 electrons. Because lithium’s final electron goes into the 2 s subshell, we write the electron configuration of a lithium atom as 1 s2 2 s1. The next largest atom, beryllium, has 4 electrons, so its electron configuration is 1 s2 2 s2. Now that the 2 s subshell is filled, electrons in larger atoms start filling the 2 p subshell. Thus, the electron configurations for the next six atoms are as follows: B: 1 s2 2 s2 2 p1 C: 1 s2 2 s2 2 p2 N: 1 s2 2 s2 2 p3 O: 1 s2 2 s2 2 p4 F: 1 s2 2 s2 2 p5 Ne: 1 s2 2 s2 2 p6 With neon, the 2 p subshell is completely filled. Because the second shell has only two subshells, atoms with more electrons now must begin the third shell. The third shell has three subshells, labeled s, p, and d. The d subshell can hold a maximum of 10 electrons. The first two subshells of the third shell are filled in order—for example, the electron configuration of aluminum, with 13 electrons, is 1 s2 2 s2 2 p6 3 s2 3 p1. However, a curious thing happens after the 3 p subshell is filled: the 4 s subshell begins to fill before the 3 d subshell does. In fact, the exact ordering of subshells becomes more complicated at this point (after argon, with its 18 electrons), so we will not consider the electron configurations of larger atoms. A fourth subshell, the f subshell, is needed to complete the electron configurations for all elements. An f subshell can hold up to 14 electrons. Example 7 What is the electron configuration of a neutral phosphorus atom? Solution A neutral phosphorus atom has 15 electrons. Two electrons can go into the 1 s subshell, 2 can go into the 2 s subshell, and 6 can go into the 2 p subshell. That leaves 5 electrons. Of those 5 electrons, 2 can go into the 3 s subshell, and the remaining 3 electrons can go into the 3 p subshell. Thus, the electron configuration of neutral phosphorus atoms is 1 s2 2 s2 2 p6 3 s2 3 p3. Skill-Building Exercise What is the electron configuration of a neutral chlorine atom? Chemistry results from interactions between the outermost shells of electrons on different atoms. Thus, it is convenient to separate electrons into two groups. Valence shell electrons An electron in the highest-numbered shell of an atom. (or, more simply, the valence electrons) are the electrons in the highest-numbered shell, or valence shell The highest-numbered shell of an atom that contains electrons. , while core electrons An electron in a lower-numbered shell of an atom. are the electrons in lower-numbered shells. We can see from the electron configuration of a carbon atom—1 s2 2 s2 2 p2 —that it has 4 valence electrons (2 s2 2 p2) and 2 core electrons (1 s2 ). Example 8 From the electron configuration of neutral phosphorus atoms in Example 7, how many valence electrons and how many core electrons does a neutral phosphorus atom have? Solution The highest-numbered shell is the third shell, which has 2 electrons in the 3 s subshell and 3 electrons in the 3 p subshell. That gives a total of 5 electrons, so neutral phosphorus atoms have 5 valence electrons. The 10 remaining electrons, from the first and second shells, are core electrons. Skill-Building Exercise From the electron configuration of neutral chlorine atoms (see the Skill-Building Exercise following Example 7), how many valence electrons and how many core electrons does a neutral chlorine atom have? Answers Electrons are organized into shells and subshells around nuclei. The electron configuration states the arrangement of electrons in shells and subshells. Valence electrons are in the highest-numbered shell; all other electrons are core electrons. Key Takeaway Electrons are organized into shells and subshells about the nucleus of an atom. Exercises What is the maximum number of electrons that can fit in an s subshell? Does it matter what shell the s subshell is in? What is the maximum number of electrons that can fit in a p subshell? Does it matter what shell the p subshell is in? What is the maximum number of electrons that can fit in a d subshell? Does it matter what shell the d subshell is in? What is the maximum number of electrons that can fit in an f subshell? Does it matter what shell the f subshell is in? What is the electron configuration of a carbon atom? What is the electron configuration of a sulfur atom? What is the valence shell electron configuration of a calcium atom? What is the valence shell electron configuration of a selenium atom? What atom has the electron configuration 1 s2 2 s2 2 p5? What atom has the electron configuration 1 s2 2 s2 2 p6 3 s2 3 p3? Draw a representation of the electronic structure of an oxygen atom. Draw a representation of the electronic structure of a phosphorus atom. A potassium atom has ____ core electrons and ____ valence electrons. A silicon atom has ____ core electrons and ____ valence electrons. Answers 2; no 10; no 1 s2 2 s2 2 p2 4 s2 fluorine 18; 1	msmarco_doc_00_11760799
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s06-03-formulas-for-ionic-compounds.html	Formulas for Ionic Compounds	3.3 Formulas for Ionic Compounds 3.3 Formulas for Ionic Compounds Learning Objectives Note Note Note Note Example 3 Skill-Building Exercise Polyatomic Ions Example 4 Skill-Building Exercise Recognizing Ionic Compounds Example 5 Skill-Building Exercise Looking Closer: Blood and Seawater Answers Key Takeaways Exercises Answers	Formulas for Ionic Compounds 3.3 Formulas for Ionic Compounds Learning Objectives Write the chemical formula for a simple ionic compound. Recognize polyatomic ions in chemical formulas. We have already encountered some chemical formulas for simple ionic compounds. A chemical formula A concise list of the elements in a compound and the ratios of these elements. is a concise list of the elements in a compound and the ratios of these elements. To better understand what a chemical formula means, we must consider how an ionic compound is constructed from its ions. Ionic compounds exist as alternating positive and negative ions in regular, three-dimensional arrays called crystals A three-dimensional array of alternating positive and negative ions. ( Figure 3.6 "A Sodium Chloride Crystal" ). As you can see, there are no individual NaCl “particles” in the array; instead, there is a continuous lattice of alternating sodium and chloride ions. However, we can use the ratio of sodium ions to chloride ions, expressed in the lowest possible whole numbers, as a way of describing the compound. In the case of sodium chloride, the ratio of sodium ions to chloride ions, expressed in lowest whole numbers, is 1:1, so we use NaCl (one Na symbol and one Cl symbol) to represent the compound. Thus, NaCl is the chemical formula for sodium chloride, which is a concise way of describing the relative number of different ions in the compound. A macroscopic sample is composed of myriads of NaCl pairs; each pair called a formula unit A set of oppositely charged ions that compose an ionic compound. . Although it is convenient to think that NaCl crystals are composed of individual NaCl units, Figure 3.6 "A Sodium Chloride Crystal" shows that no single ion is exclusively associated with any other single ion. Each ion is surrounded by ions of opposite charge. Figure 3.6 A Sodium Chloride Crystal A crystal contains a three-dimensional array of alternating positive and negative ions. The precise pattern depends on the compound. A crystal of sodium chloride, shown here, is a collection of alternating sodium and chlorine ions. Note In Section 3.2 "Ions", we encountered LiBr and MgO, which are formulas for other ionic compounds. The formula for an ionic compound follows several conventions. First, the cation is written before the anion. Because most metals form cations and most nonmetals form anions, formulas typically list the metal first and then the nonmetal. Second, charges are not written in a formula. Remember that in an ionic compound, the component species are ions, not neutral atoms, even though the formula does not contain charges. Finally, the proper formula for an ionic compound always obeys the following rule: the total positive charge must equal the total negative charge. To determine the proper formula of any combination of ions, determine how many of each ion is needed to balance the total positive and negative charges in the compound. Note This rule is ultimately based on the fact that matter is, overall, electrically neutral. Note By convention, assume that there is only one atom if a subscript is not present. We do not use 1 as a subscript. If we look at the ionic compound consisting of lithium ions and bromide ions, we see that the lithium ion has a 1+ charge and the bromide ion has a 1− charge. Only one ion of each is needed to balance these charges. The formula for lithium bromide is LiBr. When an ionic compound is formed from magnesium and oxygen, the magnesium ion has a 2+ charge, and the oxygen atom has a 2− charge. Although both of these ions have higher charges than the ions in lithium bromide, they still balance each other in a one-to-one ratio. Therefore, the proper formula for this ionic compound is MgO. Now consider the ionic compound formed by magnesium and chlorine. A magnesium ion has a 2+ charge, while a chlorine ion has a 1− charge: Mg2+ Cl− Combining one ion of each does not completely balance the positive and negative charges. The easiest way to balance these charges is to assume the presence of two chloride ions for each magnesium ion: Mg2+ Cl− Cl− Now the positive and negative charges are balanced. We could write the chemical formula for this ionic compound as MgClCl, but the convention is to use a numerical subscript when there is more than one ion of a given type—MgCl 2. This chemical formula says that there are one magnesium ion and two chloride ions in this formula. (Do not read the “Cl 2 ” part of the formula as a molecule of the diatomic elemental chlorine. Chlorine does not exist as a diatomic element in this compound. Rather, it exists as two individual chloride ions.) By convention, the lowest whole number ratio is used in the formulas of ionic compounds. The formula Mg 2 Cl 4 has balanced charges with the ions in a 1:2 ratio, but it is not the lowest whole number ratio. Note By convention, the lowest whole-number ratio of the ions is used in ionic formulas. There are exceptions for certain ions, such as Hg 22+. Example 3 Write the chemical formula for an ionic compound composed of each pair of ions. the sodium ion and the sulfur ion the aluminum ion and the fluoride ion the 3+ iron ion and the oxygen ion Solution To obtain a valence shell octet, sodium forms an ion with a 1+ charge, while the sulfur ion has a 2− charge. Two sodium 1+ ions are needed to balance the 2− charge on the sulfur ion. Rather than writing the formula as NaNaS, we shorten it by convention to Na 2 S. The aluminum ion has a 3+ charge, while the fluoride ion formed by fluorine has a 1− charge. Three fluorine 1− ions are needed to balance the 3+ charge on the aluminum ion. This combination is written as AlF 3. Iron can form two possible ions, but the ion with a 3+ charge is specified here. The oxygen atom has a 2− charge as an ion. To balance the positive and negative charges, we look to the least common multiple—6: two iron 3+ ions will give 6+, while three 2− oxygen ions will give 6−, thereby balancing the overall positive and negative charges. Thus, the formula for this ionic compound is Fe 2 O 3. Skill-Building Exercise Write the chemical formula for an ionic compound composed of each pair of ions. the calcium ion and the oxygen ion the 2+ copper ion and the sulfur ion the 1+ copper ion and the sulfur ion Polyatomic Ions Some ions consist of groups of atoms bonded together and have an overall electric charge. Because these ions contain more than one atom, they are called polyatomic ions An ion with more than one atom. . Polyatomic ions have characteristic formulas, names, and charges that should be memorized. For example, NO 3− is the nitrate ion; it has one nitrogen atom and three oxygen atoms and an overall 1− charge. Table 3.1 "Some Polyatomic Ions" lists the most common polyatomic ions. Table 3.1 Some Polyatomic Ions Name Formula ammonium ion NH 4+ acetate ion C 2 H 3 O 2− (also written CH 3 CO 2−) carbonate ion CO 32− chromate ion CrO 42− dichromate ion Cr 2 O 72− hydrogen carbonate ion (bicarbonate ion) HCO 3− cyanide ion CN − hydroxide ion OH − nitrate ion NO 3− nitrite ion NO 2− permanganate ion MnO 4− phosphate ion PO 43− hydrogen phosphate ion HPO 42− dihydrogen phosphate ion H 2 PO 4− sulfate ion SO 42− hydrogen sulfate ion (bisulfate ion) HSO 4− sulfite ion SO 32− The rule for constructing formulas for ionic compounds containing polyatomic ions is the same as for formulas containing monatomic (single-atom) ions: the positive and negative charges must balance. If more than one of a particular polyatomic ion is needed to balance the charge, the entire formula for the polyatomic ion must be enclosed in parentheses, and the numerical subscript is placed outside the parentheses. This is to show that the subscript applies to the entire polyatomic ion. An example is Ba (NO 3) 2. Example 4 Write the chemical formula for an ionic compound composed of each pair of ions. the potassium ion and the sulfate ion the calcium ion and the nitrate ion Solution Potassium ions have a charge of 1+, while sulfate ions have a charge of 2−. We will need two potassium ions to balance the charge on the sulfate ion, so the proper chemical formula is K 2 SO 4. Calcium ions have a charge of 2+, while nitrate ions have a charge of 1−. We will need two nitrate ions to balance the charge on each calcium ion. The formula for nitrate must be enclosed in parentheses. Thus, we write Ca (NO 3) 2 as the formula for this ionic compound. Skill-Building Exercise Write the chemical formula for an ionic compound composed of each pair of ions. the magnesium ion and the carbonate ion the aluminum ion and the acetate ion Recognizing Ionic Compounds There are two ways to recognize ionic compounds. First, compounds between metal and nonmetal elements are usually ionic. For example, CaBr 2 contains a metallic element (calcium, a group 2A metal) and a nonmetallic element (bromine, a group 7A nonmetal). Therefore, it is most likely an ionic compound. (In fact, it is ionic.) In contrast, the compound NO 2 contains two elements that are both nonmetals (nitrogen, from group 5A, and oxygen, from group 6A). It is not an ionic compound; it belongs to the category of covalent compounds that we will study in Chapter 4 "Covalent Bonding and Simple Molecular Compounds". Also note that this combination of nitrogen and oxygen has no electric charge specified, so it is not the nitrite ion. Second, if you recognize the formula of a polyatomic ion in a compound, the compound is ionic. For example, if you see the formula Ba (NO 3) 2, you may recognize the “NO 3 ” part as the nitrate ion, NO 3−. (Remember that the convention for writing formulas for ionic compounds is not to include the ionic charge.) This is a clue that the other part of the formula, Ba, is actually the Ba 2+ ion, with the 2+ charge balancing the overall 2− charge from the two nitrate ions. Thus, this compound is also ionic. Example 5 Identify each compound as ionic or not ionic. Na 2 O PCl 3 NH 4 Cl OF 2 Solution Sodium is a metal, and oxygen is a nonmetal; therefore, Na 2 O is expected to be ionic. Both phosphorus and chlorine are nonmetals. Therefore, PCl 3 is not ionic. The NH 4 in the formula represents the ammonium ion, NH 4+, which indicates that this compound is ionic. Both oxygen and fluorine are nonmetals. Therefore, OF 2 is not ionic. Skill-Building Exercise Identify each compound as ionic or not ionic. N 2 O FeCl 3 (NH 4) 3 PO 4 SOCl 2 Looking Closer: Blood and Seawater Science has long recognized that blood and seawater have similar compositions. After all, both liquids have ionic compounds dissolved in them. The similarity may be more than mere coincidence; many scientists think that the first forms of life on Earth arose in the oceans. A closer look, however, shows that blood and seawater are quite different. A 0.9% solution of sodium chloride approximates the salt concentration found in blood. In contrast, seawater is principally a 3% sodium chloride solution, over three times the concentration in blood. Here is a comparison of the amounts of ions in blood and seawater: Ion Percent in Seawater Percent in Blood Na + 2.36 0.322 Cl − 1.94 0.366 Mg 2+ 0.13 0.002 SO 42− 0.09 — K + 0.04 0.016 Ca 2+ 0.04 0.0096 HCO 3− 0.002 0.165 HPO 42−, H 2 PO 4− — 0.01 Most ions are more abundant in seawater than they are in blood, with some important exceptions. There are far more hydrogen carbonate ions (HCO 3−) in blood than in seawater. This difference is significant because the hydrogen carbonate ion and some related ions have a crucial role in controlling the acid-base properties of blood. (For more information on the acid-base properties of blood, see Chapter 10 "Acids and Bases", Section 10.5 "Buffers" .) The amount of hydrogen phosphate ions—HPO 42− and H 2 PO 4− —in seawater is very low, but they are present in higher amounts in blood, where they also affect acid-base properties. Another notable difference is that blood does not have significant amounts of the sulfate ion (SO 42− ), but this ion is present in seawater. Answers the ratio of each kind of ion in the compound Sometimes more than one ion is needed to balance the charge on the other ion in an ionic compound. MgI 2 Na 2 O Key Takeaways Proper chemical formulas for ionic compounds balance the total positive charge with the total negative charge. Groups of atoms with an overall charge, called polyatomic ions, also exist. Exercises Write the chemical formula for the ionic compound formed by each pair of ions. Na + and Br − Mg 2+ and Br − Mg 2+ and S 2− Write the chemical formula for the ionic compound formed by each pair of ions. K + and Cl − Mg 2+ and Cl − Mg 2+ and Se 2− Write the chemical formula for the ionic compound formed by each pair of ions. Na + and N 3− Mg 2+ and N 3− Al 3+ and S 2− Write the chemical formula for the ionic compound formed by each pair of ions. Li + and N 3− Mg 2+ and P 3− Li + and P 3− Write the chemical formula for the ionic compound formed by each pair of ions. Fe 3+ and Br − Fe 2+ and Br − Au 3+ and S 2− Au + and S 2− Write the chemical formula for the ionic compound formed by each pair of ions. Cr 3+ and O 2− Cr 2+ and O 2− Pb 2+ and Cl − Pb 4+ and Cl − Write the chemical formula for the ionic compound formed by each pair of ions. Cr 3+ and NO 3− Fe 2+ and PO 43− Ca 2+ and CrO 42− Al 3+ and OH − Write the chemical formula for the ionic compound formed by each pair of ions. NH 4+ and NO 3− H + and Cr 2 O 72− Cu + and CO 32− Na + and HCO 3− For each pair of elements, determine the charge for their ions and write the proper formula for the resulting ionic compound between them. Ba and S Cs and I For each pair of elements, determine the charge for their ions and write the proper formula for the resulting ionic compound between them. K and S Sc and Br Which compounds would you predict to be ionic? Li 2 O (NH 4) 2 O CO 2 FeSO 3 C 6 H 6 C 2 H 6 O Which compounds would you predict to be ionic? Ba (OH) 2 CH 2 O NH 2 CONH 2 (NH 4) 2 CrO 4 C 8 H 18 NH 3 Answers NaBr MgBr 2 MgS Na 3 N Mg 3 N 2 Al 2 S 3 FeBr 3 FeBr 2 Au 2 S 3 Au 2 S Cr (NO 3) 3 Fe 3 (PO 4) 2 CaCrO 4 Al (OH) 3 Ba 2+, S 2−, BaS Cs +, I −, CsI ionic ionic not ionic ionic not ionic not ionic	msmarco_doc_00_11769584
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s06-ionic-bonding-and-simple-ionic.html	Ionic Bonding and Simple Ionic Compounds	Chapter 3 Ionic Bonding and Simple Ionic Compounds Chapter 3 Ionic Bonding and Simple Ionic Compounds Opening Essay 3.1 Two Types of Bonding Learning Objectives Example 1 Skill-Building Exercise Answers Key Takeaways Exercises Answers 3.2 Ions Learning Objectives Electron Transfer Lewis Diagrams Note Example 2 Skill-Building Exercise Answers Key Takeaways Exercises Answers 3.3 Formulas for Ionic Compounds Learning Objectives Example 3 Skill-Building Exercise Polyatomic Ions Example 4 Skill-Building Exercise Recognizing Ionic Compounds Example 5 Skill-Building Exercise Looking Closer: Blood and Seawater Answers Key Takeaways Exercises Answers 3.4 Ionic Nomenclature Learning Objective Naming Ions Example 6 Skill-Building Exercise Example 7 Skill-Building Exercise Naming Compounds Example 8 Skill-Building Exercise Answers Key Takeaway Exercises Answers 3.5 Formula Mass Learning Objective Example 9 Skill-Building Exercise To Your Health: Hydrates Answers Key Takeaway Exercises Answers 3.6 End-of-Chapter Material Chapter Summary Additional Exercises Answers	Ionic Bonding and Simple Ionic Compounds Chapter 3 Ionic Bonding and Simple Ionic Compounds Opening Essay We will see that the word salt has a specific meaning in chemistry, but to most people, this word refers to table salt. This kind of salt is used as a condiment throughout the world, but it was not always so abundant. Two thousand years ago, Roman soldiers received part of their pay as salt, which explains why the words salt and salary come from the same Latin root ( salarium ). Today, table salt is either mined or obtained from the evaporation of saltwater. Table salt is sodium chloride (NaCl), which is a simple compound of two elements that are necessary for the human body to function properly. Sodium, for example, is important for nerve conduction and fluid balance. In fact, human blood is about a 0.9% sodium chloride solution, and a solution called normal saline is commonly administered intravenously in hospitals. Although some salt in our diets is necessary to replenish the sodium and chloride ions that we excrete in urine and sweat, too much is unhealthy, and many people may be ingesting more salt than their bodies need. The RDI of sodium is 2,400 mg—the amount in about 1 teaspoon of salt—but the average intake of sodium in the United States is between 4,000 mg and 5,000 mg, partly because salt is a common additive in many prepared foods. Previously, the high ingestion of salt was thought to be associated with high blood pressure, but current research does not support this link. Even so, some doctors still recommend a low-salt diet (never a “no-salt” diet) for patients with high blood pressure, which may include using a salt substitute. Most salt substitutes use potassium instead of sodium, but some people complain that the potassium imparts a slightly bitter taste. There are only 118 known chemical elements but tens of millions of known chemical compounds. Compounds can be very complex combinations of atoms, but many important compounds are fairly simple. Table salt, as we have seen, consists of only two elements: sodium and chlorine. Nevertheless, the compound has properties completely different from either elemental sodium (a chemically reactive metal) or elemental chlorine (a poisonous, green gas). We will see additional examples of such differences in this chapter and Chapter 4 "Covalent Bonding and Simple Molecular Compounds", as we consider how atoms combine to form compounds. 3.1 Two Types of Bonding Learning Objectives Define the octet rule. Describe how ionic bonds are formed. Atoms can join together by forming a chemical bond A very strong attraction between two atoms. , which is a very strong attraction between two atoms. Chemical bonds are formed when electrons in different atoms interact with each other to make an arrangement that is more stable than when the atoms are apart. What causes atoms to make a chemical bond with other atoms, rather than remaining as individual atoms? A clue comes by considering the noble gas elements, the rightmost column of the periodic table. These elements—helium, neon, argon, krypton, xenon, and radon—do not form compounds very easily, which suggests that they are especially stable as lone atoms. What else do the noble gas elements have in common? Except for helium, they all have eight valence electrons. Chemists have concluded that atoms are especially stable if they have eight electrons in their outermost shell. This useful rule of thumb is called the octet rule The idea that atoms tend to have eight electrons in their valence shell. , and it is a key to understanding why compounds form. Note Of the noble gases, only krypton, xenon, and radon have been found to make compounds. There are two ways for an atom that does not have an octet of valence electrons to obtain an octet in its outer shell. One way is the transfer of electrons between two atoms until all atoms have octets. Because some atoms will lose electrons and some atoms will gain electrons, there is no overall change in the number of electrons, but individual atoms acquire a nonzero electric charge. Those that lose electrons become positively charged, and those that gain electrons become negatively charged. Charged atoms are called ions A charged atom. . Because opposite charges attract (while like charges repel), these oppositely charged ions attract each other, forming ionic bonds An attraction between oppositely charged ions. . The resulting compounds are called ionic compounds A compound formed with an ionic bond. and are the primary subject of this chapter. The second way for an atom to obtain an octet of electrons is by sharing electrons with another atom. These shared electrons simultaneously occupy the outermost shell of more than one atom. The bond made by electron sharing is called a covalent bond. Covalent bonding and covalent compounds will be discussed in Chapter 4 "Covalent Bonding and Simple Molecular Compounds". Note Despite our focus on the octet rule, we must remember that for small atoms, such as hydrogen, helium, and lithium, the first shell is, or becomes, the outermost shell and hold only two electrons. Therefore, these atoms satisfy a “duet rule” rather than the octet rule. Example 1 A sodium atom has one valence electron. Do you think it is more likely for a sodium atom to lose one electron or gain seven electrons to obtain an octet? Solution Although either event is possible, a sodium atom is more likely to lose its single valence electron. When that happens, it becomes an ion with a net positive charge. This can be illustrated as follows: Sodium atom Sodium ion 11 protons 11+ 11 protons 11+ 11 electrons 11− 10 electrons 10− 0 overall charge +1 overall charge Skill-Building Exercise A fluorine atom has seven valence electrons. Do you think it is more likely for a fluorine atom to lose seven electrons or gain one electron to obtain an octet? Answers The octet rule is the concept that atoms tend to have eight electrons in their valence electron shell. Ionic bonds are formed by the attraction between oppositely charged ions. Key Takeaways Atoms have a tendency to have eight electrons in their valence shell. The attraction of oppositely charged ions is what makes ionic bonds. Exercises Why is an ionic compound unlikely to consist of two positively charged ions? Why is an ionic compound unlikely to consist of two negatively charged ions? A calcium atom has two valence electrons. Do you think it will lose two electrons or gain six electrons to obtain an octet in its outermost electron shell? An aluminum atom has three valence electrons. Do you think it will lose three electrons or gain five electrons to obtain an octet in its outermost electron shell? A selenium atom has six valence electrons. Do you think it will lose six electrons or gain two electrons to obtain an octet in its outermost electron shell? An iodine atom has seven valence electrons. Do you think it will lose seven electrons or gain one electron to obtain an octet in its outermost electron shell? Answers Positive charges repel each other, so an ionic compound is not likely between two positively charged ions. It is more likely to lose two electrons. It is more likely to gain two electrons. 3.2 Ions Learning Objectives Define the two types of ions. Use Lewis diagrams to illustrate ion formation. Most atoms do not have eight electrons in their valence electron shell. Some atoms have only a few electrons in their outer shell, while some atoms lack only one or two electrons to have an octet. In cases where an atom has three or fewer valence electrons, the atom may lose those valence electrons quite easily until what remains is a lower shell that contains an octet. Atoms that lose electrons acquire a positive charge as a result because they are left with fewer negatively charged electrons to balance the positive charges of the protons in the nucleus. Positively charged ions are called cations A positively charged ion. . Most metals become cations when they make ionic compounds. Some atoms have nearly eight electrons in their valence shell and can gain additional valence electrons until they have an octet. When these atoms gain electrons, they acquire a negative charge because they now possess more electrons than protons. Negatively charged ions are called anions A negatively charged ion. . Most nonmetals become anions when they make ionic compounds. Note The names for positive and negative ions are pronounced CAT-eye-ons and ANN-eye-ons, respectively. Electron Transfer We can use electron configurations to illustrate the electron transfer process between sodium atoms and chlorine atoms. Recall the electron configuration of sodium from Chapter 2 "Elements, Atoms, and the Periodic Table": Na: 1s22s22p63s1 As demonstrated in Example 1 (in Section 3.1 "Two Types of Bonding" ), sodium is likely to achieve an octet in its outermost shell by losing its one valence electron. The remaining species has the following electron configuration: The cation produced in this way, Na +, is called the sodium ion to distinguish it from the element. The outermost shell of the sodium ion is the second electron shell, which has eight electrons in it. The octet rule has been satisfied. Figure 3.1 "The Formation of a Sodium Ion" is a graphical depiction of this process. Figure 3.1 The Formation of a Sodium Ion On the left, a sodium atom has 11 electrons. On the right, the sodium ion only has 10 electrons and a 1+ charge. A chlorine atom has the following electron configuration: Cl: 1s22s22p63s23p5 Only one more electron is needed to achieve an octet in chlorine’s valence shell. (In table salt, this electron comes from the sodium atom.) The electron configuration of the new species that results is as follows: In this case, the ion has the same outermost shell as the original atom, but now that shell has eight electrons in it. Once again, the octet rule has been satisfied. The resulting anion, Cl −, is called the chloride ion; note the slight change in the suffix (- ide instead of - ine) to create the name of this anion. Figure 3.2 "The Formation of a Chlorine Ion" is a graphical depiction of this process. Figure 3.2 The Formation of a Chlorine Ion On the left, the chlorine atom has 17 electrons. On the right, the chloride ion has 18 electrons and has a 1− charge. With two oppositely charged ions, there is an electrostatic attraction between them because opposite charges attract. The resulting combination is the compound sodium chloride. Notice that there are no leftover electrons. The number of electrons lost by the sodium atom (one) equals the number of electrons gained by the chlorine atom (one), so the compound is electrically neutral. In macroscopic samples of sodium chloride, there are billions and billions of sodium and chloride ions, although there is always the same number of cations and anions. In many cases, elements that belong to the same group (vertical column) on the periodic table form ions with the same charge because they have the same number of valence electrons. Thus, the periodic table becomes a tool for remembering the charges on many ions. For example, all ions made from alkali metals, the first column on the periodic table, have a 1+ charge. Ions made from alkaline earth metals, the second group on the periodic table, have a 2+ charge. On the other side of the periodic table, the next-to-last column, the halogens, form ions having a 1− charge. Figure 3.3 "Predicting Ionic Charges" shows how the charge on many ions can be predicted by the location of an element on the periodic table. Note the convention of first writing the number and then the sign on a multiply charged ion. The barium cation is written Ba 2+, not Ba +2. Figure 3.3 Predicting Ionic Charges The charge that an atom acquires when it becomes an ion is related to the structure of the periodic table. Within a group (family) of elements, atoms form ions of a certain charge. Lewis Diagrams Chemists use simple diagrams to show an atom’s valence electrons and how they transfer. These diagrams have two advantages over the electron shell diagrams introduced in Chapter 2 "Elements, Atoms, and the Periodic Table". First, they show only valence electrons. Second, instead of having a circle around the chemical symbol to represent the electron shell, they have up to eight dots around the symbol; each dot represents a valence electron. These dots are arranged to the right and left and above and below the symbol, with no more than two dots on a side. For example, the representation for sodium is as follows: and the representation for chlorine is as follows: Note It does not matter what sides the dots are placed on in Lewis diagrams as long as each side has a maximum of two dots. These diagrams are called Lewis electron dot diagrams, or simply Lewis diagrams A representation that shows valence electrons as dots around the chemical symbol of an atom (also called Lewis electron dot diagrams). , after Gilbert N. Lewis, the American chemist who introduced them. Figure 3.4 "Lewis Diagrams of the Elements Lithium through Neon" shows the electron configurations and Lewis diagrams of the elements lithium through neon, which is the entire second period of the periodic table. For the main group elements, the number of valence electrons is the same as the group number listed at the top of the periodic table. Figure 3.4 Lewis Diagrams of the Elements Lithium through Neon The transfer of electrons can be illustrated easily with Lewis diagrams: In representing the final formula, the dots are omitted. Example 2 Starting with lithium and bromine atoms, use Lewis diagrams to show the formation of the ionic compound LiBr. Solution From the periodic table, we see that lithium is in the same column as sodium, so it will have the same valence shell electron configuration. That means that the neutral lithium atom will have the same Lewis diagram that the sodium atom has. Similarly, bromine is in the same column as chlorine, so it will have the same Lewis diagram that chlorine has. Therefore, Skill-Building Exercise Starting with magnesium and oxygen atoms, use Lewis diagrams to show the formation of the ionic compound MgO. Some ionic compounds have different numbers of cations and anions. In those cases, electron transfer occurs between more than one atom. For example, here is the formation of MgBr 2: Most of the elements that make ionic compounds form an ion that has a characteristic charge. For example, sodium makes ionic compounds in which the sodium ion always has a 1+ charge. Chlorine makes ionic compounds in which the chloride ion always has a 1− charge. Some elements, especially transition metals, can form ions of multiple charges. Figure 3.5 "Charges of the Monatomic Ions" shows the characteristic charges for some of these ions. As we saw in Figure 3.1 "The Formation of a Sodium Ion", there is a pattern to the charges on many of the main group ions, but there is no simple pattern for transition metal ions (or for the larger main group elements). Figure 3.5 Charges of the Monatomic Ions Note that some atoms commonly form ions of different charges. Answers Cations have positive charges, and anions have negative charges. 1+ 2− 2+ 1− Key Takeaways Ions can be positively charged or negatively charged. A Lewis diagram is used to show how electrons are transferred to make ions and ionic compounds. Exercises Identify each as a cation, an anion, or neither. H + Cl − O 2 Ba 2+ CH 4 CS 2 Identify each as a cation, an anion, or neither. NH 3 Br − H − Hg 2+ CCl 4 SO 3 Write the electron configuration for each ion. Li + Mg 2+ F − S 2− Write the electron configuration for each ion. Na + Be 2+ Cl − O 2− Draw Lewis diagrams for the ions listed in Exercise 3. Also include Lewis diagrams for the respective neutral atoms as a comparison. Draw Lewis diagrams for the ions listed in Exercise 4. Also include Lewis diagrams for the respective neutral atoms as a comparison. Using Lewis diagrams, show the electron transfer for the formation of LiF. Using Lewis diagrams, show the electron transfer for the formation of MgO. Using Lewis diagrams, show the electron transfer for the formation of Li 2 O. Using Lewis diagrams, show the electron transfer for the formation of CaF 2. What characteristic charge do atoms in the first column of the periodic table have when they become ions? What characteristic charge do atoms in the second column of the periodic table have when they become ions? What characteristic charge do atoms in the third-to-last column of the periodic table have when they become ions? What characteristic charge do atoms in the next-to-last column of the periodic table have when they become ions? Answers cation anion neither cation neither neither 1 s2 1 s2 2 s2 2 p6 1 s2 2 s2 2 p6 1 s2 2 s2 2 p6 3 s2 3 p6 1+ 2− 3.3 Formulas for Ionic Compounds Learning Objectives Write the chemical formula for a simple ionic compound. Recognize polyatomic ions in chemical formulas. We have already encountered some chemical formulas for simple ionic compounds. A chemical formula A concise list of the elements in a compound and the ratios of these elements. is a concise list of the elements in a compound and the ratios of these elements. To better understand what a chemical formula means, we must consider how an ionic compound is constructed from its ions. Ionic compounds exist as alternating positive and negative ions in regular, three-dimensional arrays called crystals A three-dimensional array of alternating positive and negative ions. ( Figure 3.6 "A Sodium Chloride Crystal" ). As you can see, there are no individual NaCl “particles” in the array; instead, there is a continuous lattice of alternating sodium and chloride ions. However, we can use the ratio of sodium ions to chloride ions, expressed in the lowest possible whole numbers, as a way of describing the compound. In the case of sodium chloride, the ratio of sodium ions to chloride ions, expressed in lowest whole numbers, is 1:1, so we use NaCl (one Na symbol and one Cl symbol) to represent the compound. Thus, NaCl is the chemical formula for sodium chloride, which is a concise way of describing the relative number of different ions in the compound. A macroscopic sample is composed of myriads of NaCl pairs; each pair called a formula unit A set of oppositely charged ions that compose an ionic compound. . Although it is convenient to think that NaCl crystals are composed of individual NaCl units, Figure 3.6 "A Sodium Chloride Crystal" shows that no single ion is exclusively associated with any other single ion. Each ion is surrounded by ions of opposite charge. Figure 3.6 A Sodium Chloride Crystal A crystal contains a three-dimensional array of alternating positive and negative ions. The precise pattern depends on the compound. A crystal of sodium chloride, shown here, is a collection of alternating sodium and chlorine ions. Note In Section 3.2 "Ions", we encountered LiBr and MgO, which are formulas for other ionic compounds. The formula for an ionic compound follows several conventions. First, the cation is written before the anion. Because most metals form cations and most nonmetals form anions, formulas typically list the metal first and then the nonmetal. Second, charges are not written in a formula. Remember that in an ionic compound, the component species are ions, not neutral atoms, even though the formula does not contain charges. Finally, the proper formula for an ionic compound always obeys the following rule: the total positive charge must equal the total negative charge. To determine the proper formula of any combination of ions, determine how many of each ion is needed to balance the total positive and negative charges in the compound. Note This rule is ultimately based on the fact that matter is, overall, electrically neutral. Note By convention, assume that there is only one atom if a subscript is not present. We do not use 1 as a subscript. If we look at the ionic compound consisting of lithium ions and bromide ions, we see that the lithium ion has a 1+ charge and the bromide ion has a 1− charge. Only one ion of each is needed to balance these charges. The formula for lithium bromide is LiBr. When an ionic compound is formed from magnesium and oxygen, the magnesium ion has a 2+ charge, and the oxygen atom has a 2− charge. Although both of these ions have higher charges than the ions in lithium bromide, they still balance each other in a one-to-one ratio. Therefore, the proper formula for this ionic compound is MgO. Now consider the ionic compound formed by magnesium and chlorine. A magnesium ion has a 2+ charge, while a chlorine ion has a 1− charge: Mg2+ Cl− Combining one ion of each does not completely balance the positive and negative charges. The easiest way to balance these charges is to assume the presence of two chloride ions for each magnesium ion: Mg2+ Cl− Cl− Now the positive and negative charges are balanced. We could write the chemical formula for this ionic compound as MgClCl, but the convention is to use a numerical subscript when there is more than one ion of a given type—MgCl 2. This chemical formula says that there are one magnesium ion and two chloride ions in this formula. (Do not read the “Cl 2 ” part of the formula as a molecule of the diatomic elemental chlorine. Chlorine does not exist as a diatomic element in this compound. Rather, it exists as two individual chloride ions.) By convention, the lowest whole number ratio is used in the formulas of ionic compounds. The formula Mg 2 Cl 4 has balanced charges with the ions in a 1:2 ratio, but it is not the lowest whole number ratio. Note By convention, the lowest whole-number ratio of the ions is used in ionic formulas. There are exceptions for certain ions, such as Hg 22+. Example 3 Write the chemical formula for an ionic compound composed of each pair of ions. the sodium ion and the sulfur ion the aluminum ion and the fluoride ion the 3+ iron ion and the oxygen ion Solution To obtain a valence shell octet, sodium forms an ion with a 1+ charge, while the sulfur ion has a 2− charge. Two sodium 1+ ions are needed to balance the 2− charge on the sulfur ion. Rather than writing the formula as NaNaS, we shorten it by convention to Na 2 S. The aluminum ion has a 3+ charge, while the fluoride ion formed by fluorine has a 1− charge. Three fluorine 1− ions are needed to balance the 3+ charge on the aluminum ion. This combination is written as AlF 3. Iron can form two possible ions, but the ion with a 3+ charge is specified here. The oxygen atom has a 2− charge as an ion. To balance the positive and negative charges, we look to the least common multiple—6: two iron 3+ ions will give 6+, while three 2− oxygen ions will give 6−, thereby balancing the overall positive and negative charges. Thus, the formula for this ionic compound is Fe 2 O 3. Skill-Building Exercise Write the chemical formula for an ionic compound composed of each pair of ions. the calcium ion and the oxygen ion the 2+ copper ion and the sulfur ion the 1+ copper ion and the sulfur ion Polyatomic Ions Some ions consist of groups of atoms bonded together and have an overall electric charge. Because these ions contain more than one atom, they are called polyatomic ions An ion with more than one atom. . Polyatomic ions have characteristic formulas, names, and charges that should be memorized. For example, NO 3− is the nitrate ion; it has one nitrogen atom and three oxygen atoms and an overall 1− charge. Table 3.1 "Some Polyatomic Ions" lists the most common polyatomic ions. Table 3.1 Some Polyatomic Ions Name Formula ammonium ion NH 4+ acetate ion C 2 H 3 O 2− (also written CH 3 CO 2−) carbonate ion CO 32− chromate ion CrO 42− dichromate ion Cr 2 O 72− hydrogen carbonate ion (bicarbonate ion) HCO 3− cyanide ion CN − hydroxide ion OH − nitrate ion NO 3− nitrite ion NO 2− permanganate ion MnO 4− phosphate ion PO 43− hydrogen phosphate ion HPO 42− dihydrogen phosphate ion H 2 PO 4− sulfate ion SO 42− hydrogen sulfate ion (bisulfate ion) HSO 4− sulfite ion SO 32− The rule for constructing formulas for ionic compounds containing polyatomic ions is the same as for formulas containing monatomic (single-atom) ions: the positive and negative charges must balance. If more than one of a particular polyatomic ion is needed to balance the charge, the entire formula for the polyatomic ion must be enclosed in parentheses, and the numerical subscript is placed outside the parentheses. This is to show that the subscript applies to the entire polyatomic ion. An example is Ba (NO 3) 2. Example 4 Write the chemical formula for an ionic compound composed of each pair of ions. the potassium ion and the sulfate ion the calcium ion and the nitrate ion Solution Potassium ions have a charge of 1+, while sulfate ions have a charge of 2−. We will need two potassium ions to balance the charge on the sulfate ion, so the proper chemical formula is K 2 SO 4. Calcium ions have a charge of 2+, while nitrate ions have a charge of 1−. We will need two nitrate ions to balance the charge on each calcium ion. The formula for nitrate must be enclosed in parentheses. Thus, we write Ca (NO 3) 2 as the formula for this ionic compound. Skill-Building Exercise Write the chemical formula for an ionic compound composed of each pair of ions. the magnesium ion and the carbonate ion the aluminum ion and the acetate ion Recognizing Ionic Compounds There are two ways to recognize ionic compounds. First, compounds between metal and nonmetal elements are usually ionic. For example, CaBr 2 contains a metallic element (calcium, a group 2A metal) and a nonmetallic element (bromine, a group 7A nonmetal). Therefore, it is most likely an ionic compound. (In fact, it is ionic.) In contrast, the compound NO 2 contains two elements that are both nonmetals (nitrogen, from group 5A, and oxygen, from group 6A). It is not an ionic compound; it belongs to the category of covalent compounds that we will study in Chapter 4 "Covalent Bonding and Simple Molecular Compounds". Also note that this combination of nitrogen and oxygen has no electric charge specified, so it is not the nitrite ion. Second, if you recognize the formula of a polyatomic ion in a compound, the compound is ionic. For example, if you see the formula Ba (NO 3) 2, you may recognize the “NO 3 ” part as the nitrate ion, NO 3−. (Remember that the convention for writing formulas for ionic compounds is not to include the ionic charge.) This is a clue that the other part of the formula, Ba, is actually the Ba 2+ ion, with the 2+ charge balancing the overall 2− charge from the two nitrate ions. Thus, this compound is also ionic. Example 5 Identify each compound as ionic or not ionic. Na 2 O PCl 3 NH 4 Cl OF 2 Solution Sodium is a metal, and oxygen is a nonmetal; therefore, Na 2 O is expected to be ionic. Both phosphorus and chlorine are nonmetals. Therefore, PCl 3 is not ionic. The NH 4 in the formula represents the ammonium ion, NH 4+, which indicates that this compound is ionic. Both oxygen and fluorine are nonmetals. Therefore, OF 2 is not ionic. Skill-Building Exercise Identify each compound as ionic or not ionic. N 2 O FeCl 3 (NH 4) 3 PO 4 SOCl 2 Looking Closer: Blood and Seawater Science has long recognized that blood and seawater have similar compositions. After all, both liquids have ionic compounds dissolved in them. The similarity may be more than mere coincidence; many scientists think that the first forms of life on Earth arose in the oceans. A closer look, however, shows that blood and seawater are quite different. A 0.9% solution of sodium chloride approximates the salt concentration found in blood. In contrast, seawater is principally a 3% sodium chloride solution, over three times the concentration in blood. Here is a comparison of the amounts of ions in blood and seawater: Ion Percent in Seawater Percent in Blood Na + 2.36 0.322 Cl − 1.94 0.366 Mg 2+ 0.13 0.002 SO 42− 0.09 — K + 0.04 0.016 Ca 2+ 0.04 0.0096 HCO 3− 0.002 0.165 HPO 42−, H 2 PO 4− — 0.01 Most ions are more abundant in seawater than they are in blood, with some important exceptions. There are far more hydrogen carbonate ions (HCO 3−) in blood than in seawater. This difference is significant because the hydrogen carbonate ion and some related ions have a crucial role in controlling the acid-base properties of blood. (For more information on the acid-base properties of blood, see Chapter 10 "Acids and Bases", Section 10.5 "Buffers" .) The amount of hydrogen phosphate ions—HPO 42− and H 2 PO 4− —in seawater is very low, but they are present in higher amounts in blood, where they also affect acid-base properties. Another notable difference is that blood does not have significant amounts of the sulfate ion (SO 42− ), but this ion is present in seawater. Answers the ratio of each kind of ion in the compound Sometimes more than one ion is needed to balance the charge on the other ion in an ionic compound. MgI 2 Na 2 O Key Takeaways Proper chemical formulas for ionic compounds balance the total positive charge with the total negative charge. Groups of atoms with an overall charge, called polyatomic ions, also exist. Exercises Write the chemical formula for the ionic compound formed by each pair of ions. Na + and Br − Mg 2+ and Br − Mg 2+ and S 2− Write the chemical formula for the ionic compound formed by each pair of ions. K + and Cl − Mg 2+ and Cl − Mg 2+ and Se 2− Write the chemical formula for the ionic compound formed by each pair of ions. Na + and N 3− Mg 2+ and N 3− Al 3+ and S 2− Write the chemical formula for the ionic compound formed by each pair of ions. Li + and N 3− Mg 2+ and P 3− Li + and P 3− Write the chemical formula for the ionic compound formed by each pair of ions. Fe 3+ and Br − Fe 2+ and Br − Au 3+ and S 2− Au + and S 2− Write the chemical formula for the ionic compound formed by each pair of ions. Cr 3+ and O 2− Cr 2+ and O 2− Pb 2+ and Cl − Pb 4+ and Cl − Write the chemical formula for the ionic compound formed by each pair of ions. Cr 3+ and NO 3− Fe 2+ and PO 43− Ca 2+ and CrO 42− Al 3+ and OH − Write the chemical formula for the ionic compound formed by each pair of ions. NH 4+ and NO 3− H + and Cr 2 O 72− Cu + and CO 32− Na + and HCO 3− For each pair of elements, determine the charge for their ions and write the proper formula for the resulting ionic compound between them. Ba and S Cs and I For each pair of elements, determine the charge for their ions and write the proper formula for the resulting ionic compound between them. K and S Sc and Br Which compounds would you predict to be ionic? Li 2 O (NH 4) 2 O CO 2 FeSO 3 C 6 H 6 C 2 H 6 O Which compounds would you predict to be ionic? Ba (OH) 2 CH 2 O NH 2 CONH 2 (NH 4) 2 CrO 4 C 8 H 18 NH 3 Answers NaBr MgBr 2 MgS Na 3 N Mg 3 N 2 Al 2 S 3 FeBr 3 FeBr 2 Au 2 S 3 Au 2 S Cr (NO 3) 3 Fe 3 (PO 4) 2 CaCrO 4 Al (OH) 3 Ba 2+, S 2−, BaS Cs +, I −, CsI ionic ionic not ionic ionic not ionic not ionic 3.4 Ionic Nomenclature Learning Objective Use the rules for naming ionic compounds. After learning a few more details about the names of individual ions, you will be a step away from knowing how to name ionic compounds. This section begins the formal study of nomenclature The systematic naming of chemical compounds. , the systematic naming of chemical compounds. Naming Ions The name of a monatomic cation is simply the name of the element followed by the word ion. Thus, Na + is the sodium ion, Al 3+ is the aluminum ion, Ca 2+ is the calcium ion, and so forth. We have seen that some elements lose different numbers of electrons, producing ions of different charges ( Figure 3.3 "Predicting Ionic Charges" ). Iron, for example, can form two cations, each of which, when combined with the same anion, makes a different compound with unique physical and chemical properties. Thus, we need a different name for each iron ion to distinguish Fe 2+ from Fe 3+. The same issue arises for other ions with more than one possible charge. There are two ways to make this distinction. In the simpler, more modern approach, called the Stock system The system of indicating a cation’s charge with roman numerals. , an ion’s positive charge is indicated by a roman numeral in parentheses after the element name, followed by the word ion. Thus, Fe 2+ is called the iron (II) ion, while Fe 3+ is called the iron (III) ion. This system is used only for elements that form more than one common positive ion. We do not call the Na + ion the sodium (I) ion because (I) is unnecessary. Sodium forms only a 1+ ion, so there is no ambiguity about the name sodium ion. The second system, called the common system, is not conventional but is still prevalent and used in the health sciences. This system recognizes that many metals have two common cations. The common system uses two suffixes (- ic and - ous) that are appended to the stem of the element name. The -ic suffix represents the greater of the two cation charges, and the -ous suffix represents the lower one. In many cases, the stem of the element name comes from the Latin name of the element. Table 3.2 "The Common System of Cation Names" lists the elements that use the common system, along with their respective cation names. Table 3.2 The Common System of Cation Names Element Stem Charge Name iron ferr- 2+ ferrous ion 3+ ferric ion copper cupr- 1+ cuprous ion 2+ cupric ion tin stann- 2+ stannous ion 4+ stannic ion lead plumb- 2+ plumbous ion 4+ plumbic ion chromium chrom- 2+ chromous ion 3+ chromic ion gold aur- 1+ aurous ion 3+ auric ion The name of a monatomic anion consists of the stem of the element name, the suffix - ide, and then the word ion. Thus, as we have already seen, Cl − is “chlor-” + “-ide ion,” or the chloride ion. Similarly, O 2− is the oxide ion, Se 2− is the selenide ion, and so forth. Table 3.3 "Some Monatomic Anions" lists the names of some common monatomic ions. Table 3.3 Some Monatomic Anions Ion Name F − fluoride ion Cl − chloride ion Br − bromide ion I − iodide ion O 2− oxide ion S 2− sulfide ion P 3− phosphide ion N 3− nitride ion The polyatomic ions have their own characteristic names, as we saw in Table 3.1 "Some Polyatomic Ions". Example 6 Name each ion. Ca 2+ S 2− SO 32− NH 4+ Cu + Solution the calcium ion the sulfide ion (from Table 3.3 "Some Monatomic Anions") the sulfite ion (from Table 3.1 "Some Polyatomic Ions") the ammonium ion (from Table 3.1 "Some Polyatomic Ions") the copper (I) ion or the cuprous ion ( Figure 3.5 "Charges of the Monatomic Ions" shows that copper can form cations with either a 1+ or 2+ charge, so we have to specify which charge this ion has) Skill-Building Exercise Name each ion. Fe 2+ Fe 3+ SO 42− Ba 2+ HCO 3− Example 7 Write the formula for each ion. the bromide ion the phosphate ion the cupric ion the magnesium ion Solution Br − PO 43− Cu 2+ Mg 2+ Skill-Building Exercise Write the formula for each ion. the fluoride ion the carbonate ion the stannous ion the potassium ion Naming Compounds Now that we know how to name ions, we are ready to name ionic compounds. We do so by placing the name of the cation first, followed by the name of the anion, and dropping the word ion from both parts. For example, what is the name of the compound whose formula is Ba (NO 3) 2? The compound’s name does not indicate that there are two nitrate ions for every barium ion. You must determine the relative numbers of ions by balancing the positive and negative charges. If you are given a formula for an ionic compound whose cation can have more than one possible charge, you must first determine the charge on the cation before identifying its correct name. For example, consider FeCl 2 and FeCl 3. In the first compound, the iron ion has a 2+ charge because there are two Cl − ions in the formula (1− charge on each chloride ion). In the second compound, the iron ion has a 3+ charge, as indicated by the three Cl − ions in the formula. These are two different compounds that need two different names. By the Stock system, the names are iron (II) chloride and iron (III) chloride. If we were to use the stems and suffixes of the common system, the names would be ferrous chloride and ferric chloride, respectively. Example 8 Name each ionic compound, using both Stock and common systems if necessary. Ca 3 (PO 4) 2 (NH 4) 2 Cr 2 O 7 KCl CuCl SnF 2 Solution calcium phosphate ammonium dichromate (the prefix di - is part of the name of the anion, as in Table 3.1 "Some Polyatomic Ions") potassium chloride copper (I) chloride or cuprous chloride tin (II) fluoride or stannous fluoride Skill-Building Exercise Name each ionic compound, using both Stock and common systems if necessary. ZnBr 2 Fe (NO 3) 3 Al 2 O 3 AuF 3 AgF Figure 3.7 "A Guide to Naming Simple Ionic Compounds" is a synopsis of how to name simple ionic compounds. Figure 3.7 A Guide to Naming Simple Ionic Compounds Follow these steps to name a simple ionic compound. Answers Name the cation and then the anion but don’t use numerical prefixes. the cation name followed by the anion name Ionic compounds in which the cation can have more than one possible charge have two naming systems. FeCl 3 is either iron (III) chloride or ferric chloride (answers will vary). Key Takeaway Each ionic compound has its own unique name that comes from the names of the ions. Exercises Name each ion. Ra 2+ P 3− H 2 PO 4− Sn 4+ Name each ion. Cs + As 3− HSO 4− Sn 2+ Name the ionic compound formed by each pair of ions. Na + and Br − Mg 2+ and Br − Mg 2+ and S 2− Name the ionic compound formed by each pair of ions. K + and Cl − Mg 2+ and Cl − Mg 2+ and Se 2− Name the ionic compound formed by each pair of ions. Na + and N 3− Mg 2+ and N 3− Al 3+ and S 2− Name the ionic compound formed by each pair of ions. Li + and N 3− Mg 2+ and P 3− Li + and P 3− Name the ionic compound formed by each pair of ions. Use both the Stock and common systems, where appropriate. Fe 3+ and Br − Fe 2+ and Br − Au 3+ and S 2− Au + and S 2− Name the ionic compound formed by each pair of ions. Use both the Stock and common systems, where appropriate. Cr 3+ and O 2− Cr 2+ and O 2− Pb 2+ and Cl − Pb 4+ and Cl − Name the ionic compound formed by each pair of ions. Use both the Stock and common systems, where appropriate. Cr 3+ and NO 3− Fe 2+ and PO 43− Ca 2+ and CrO 42− Al 3+ and OH − Name the ionic compound formed by each pair of ions. Use both the Stock and common systems, where appropriate. NH 4+ and NO 3− H + and Cr 2 O 72− Cu + and CO 32− Na + and HCO 3− Give two names for each compound. Al (HSO 4) 3 Mg (HSO 4) 2 Give two names for each compound. Co (HCO 3) 2 LiHCO 3 Answers the radium ion the phosphide ion the dihydrogen phosphate ion the tin (IV) ion or the stannic ion sodium bromide magnesium bromide magnesium sulfide sodium nitride magnesium nitride aluminum sulfide iron (III) bromide or ferric bromide iron (II) bromide or ferrous bromide gold (III) sulfide or auric sulfide gold (I) sulfide or aurous sulfide chromium (III) nitrate or chromic nitrate iron (II) phosphate or ferrous phosphate calcium chromate aluminum hydroxide aluminum hydrogen sulfate or aluminum bisulfate magnesium hydrogen sulfate or magnesium bisulfate 3.5 Formula Mass Learning Objective Determine the formula mass of an ionic compound. One skill needed in future chapters is the ability to determine the mass of the formula of an ionic compound. This quantity is called the formula mass The sum of the masses of the elements in the formula of an ionic compound. . The formula mass is obtained by adding the masses of each individual atom in the formula of the compound. Because a proper formula is electrically neutral (with no net electrons gained or lost), the ions can be considered atoms for the purpose of calculating the formula mass. Let us start by calculating the formula mass of sodium chloride (NaCl). This formula mass is the sum of the atomic masses of one sodium atom and one chlorine atom, which we find from the periodic table; here, we use the masses to two decimal places: Na: 22.99 u Cl: + 35.45 u Total: 58.44 u To two decimal places, the formula mass of NaCl is 58.44 u. When an ionic compound has more than one anion or cation, you must remember to use the proper multiple of the atomic mass for the element in question. For the formula mass of calcium fluoride (CaF 2 ), we must multiply the mass of the fluorine atom by 2 to account for the two fluorine atoms in the chemical formula: Ca: 1 × 40.08 40.08 u F: 2 × 19.00 = + 38.00 u Total: 78.08 u The formula mass of CaF 2 is 78.08 u. For ionic compounds with polyatomic ions, the sum must include the number and mass of each atom in the formula for the polyatomic ion. For example, potassium nitrate (KNO 3) has one potassium atom, one nitrogen atom, and three oxygen atoms: K: 1 × 39.10 39.10 u N: 1 × 14.00 + 14.00 u O: 3 × 16.00 = + 48.00 u Total: 101.10 u The formula mass of KNO 3 is 101.10 u. Note Potassium nitrate is a key ingredient in gunpowder and has been used clinically as a diuretic. When a formula contains more than one polyatomic unit in the chemical formula, as in Ca (NO 3) 2, don’t forget to multiply the atomic mass of every atom inside the parentheses by the subscript outside the parentheses. This is necessary because the subscript refers to the entire polyatomic ion. Thus, for Ca (NO 3) 2, the subscript 2 implies two complete nitrate ions, so we must sum the masses of two (1 × 2) nitrogen atoms and six (3 × 2) oxygen atoms, along with the mass of a single calcium atom: Ca: 1 × 40.08 40.08 u N: 2 × 14.00 = + 28.00 u O: 6 × 16.00 = + 96.00 u Total: 164.08 u The key to calculating the formula mass of an ionic compound is to correctly count each atom in the formula and multiply the atomic masses of its atoms accordingly. Example 9 Use the atomic masses (rounded to two decimal places) from the inside cover of this book to determine the formula mass for each ionic compound. FeCl 3 (NH 4) 3 PO 4 Solution Fe: 55.85 u Cl: 3 × 35.45 = + 106.35 u Total: 162.20 u The formula mass of FeCl 3 is 162.20 u. When we distribute the subscript 3 through the parentheses containing the formula for the ammonium ion, we see that we have 3 nitrogen atoms and 12 hydrogen atoms. Thus, we set up the sum as follows: N: 3 × 14.00 = 42.00 u H: 12 × 1.00 = + 12.00 u P: + 30.97 u O: 4 × 16.00 = + 64.00 u Total: 148.97 u The formula mass for (NH 4) 3 PO 4 is 148.97 u. Skill-Building Exercise Use the atomic masses (rounded to two decimal places) from the inside cover of this book to determine the formula mass for each ionic compound. TiO 2 AgBr Au (NO 3) 3 Fe 3 (PO 4) 2 To Your Health: Hydrates Some ionic compounds have water (H 2 O) incorporated within their formula unit. These compounds, called hydrates, have a characteristic number of water units associated with each formula unit of the compound. Hydrates are solids, not liquids or solutions, despite the water they contain. To write the chemical formula of a hydrate, write the number of water units per formula unit of compound after its chemical formula. The two chemical formulas are separated by a vertically centered dot. The hydrate of copper (II) sulfate has five water units associated with each formula unit, so it is written as CuSO 4 ·5H 2 O. The name of this compound is copper (II) sulfate pentahydrate, with the penta- prefix indicating the presence of five water units per formula unit of copper (II) sulfate. Hydrates have various uses in the health industry. Calcium sulfate hemihydrate (CaSO 4 ·½H 2 O), known as plaster of Paris, is used to make casts for broken bones. Epsom salt (MgSO 4 ·7H 2 O) is used as a bathing salt and a laxative. Aluminum chloride hexahydrate is an active ingredient in antiperspirants. The accompanying table lists some useful hydrates. Calcium sulfate hemihydrate (CaSO 4 ·½H 2 O), or plaster of Paris, is used to make casts to immobilize broken bones until they heal. © Thinkstock Table 3.4 Names and Formulas of Some Widely Used Hydrates Formula Name Uses AlCl 3 ·6H 2 O aluminum chloride hexahydrate antiperspirant CaSO 4 ·½H 2 O calcium sulfate hemihydrate (plaster of Paris) casts (for broken bones and castings) CaSO 4 ·2H 2 O calcium sulfate dihydrate (gypsum) drywall component CoCl 2 ·6H 2 O cobalt (II) chloride hexahydrate drying agent, humidity indicator CuSO 4 ·5H 2 O copper (II) sulfate pentahydrate fungicide, algicide, herbicide MgSO 4 ·7H 2 O magnesium sulfate heptahydrate (Epsom salts) laxative, bathing salt Na 2 CO 3 ·10H 2 O sodium carbonate decahydrate (washing soda) laundry additive/cleaner Answers The formula mass is the sum of the atomic masses of the atoms in the formula. The subscript is distributed throughout the parentheses to determine the total number of atoms in the formula. Key Takeaway Formula masses of ionic compounds can be determined from the masses of the atoms in their formulas. Exercises What is the formula mass for the ionic compound formed by each pair of ions? Na + and Br − Mg 2+ and Br − Mg 2+ and S 2− What is the formula mass for the ionic compound formed by each pair of ions? K + and Cl − Mg 2+ and Cl − Mg 2+ and Se 2− What is the formula mass for the ionic compound formed by each pair of ions? Na + and N 3− Mg 2+ and N 3− Al 3+ and S 2− What is the formula mass for the ionic compound formed by each pair of ions? Li + and N 3− Mg 2+ and P 3− Li + and P 3− What is the formula mass for each compound? FeBr 3 FeBr 2 Au 2 S 3 Au 2 S What is the formula mass for each compound? Cr 2 O 3 CrO PbCl 2 PbCl 4 What is the formula mass for each compound? Cr (NO 3) 3 Fe 3 (PO 4) 2 CaCrO 4 Al (OH) 3 What is the formula mass for each compound? NH 4 NO 3 H 2 Cr 2 O 7 Cu 2 CO 3 NaHCO 3 What is the formula mass for each compound? Al (HSO 4) 3 Mg (HSO 4) 2 What is the formula mass for each compound? Co (HCO 3) 2 LiHCO 3 Answers 102.90 u 184.11 u 56.38 u 83.00 u 100.93 u 150.17 u 295.50 u 215.60 u 490.30 u 426.10 u 238.00 u 357.49 u 156.08 u 78.01 u 318.22 u 218.47 u 3.6 End-of-Chapter Material Chapter Summary To ensure that you understand the material in this chapter, you should review the meanings of the following bold terms and ask yourself how they relate to the topics in the chapter. Atoms combine into compounds by forming chemical bonds. A survey of stable atoms and molecules leads to the octet rule, which says that stable atoms tend to have eight electrons in their outermost, or valence, shell. One way atoms obtain eight electrons in the valence shell is for some atoms to lose electrons while other atoms gain them. When this happens, the atoms take on an electrical charge. Charged atoms are called ions. Ions having opposite charges attract each other. This attraction is called ionic bonding, and the compounds formed are called ionic compounds. Positively charged ions are called cations, while negatively charged ions are called anions. The formation of both cations and anions can be illustrated using electron configurations. Because elements in a column of the periodic table have the same valence shell electron configuration, atoms in the same column of the periodic table tend to form ions having the same charge. Electron dot diagrams, or Lewis diagrams, can also be used to illustrate the formation of cations and anions. Ionic compounds are represented in writing by a chemical formula, which gives the lowest ratio of cations and anions present in the compound. In a formula, the symbol of the cation is written first, followed by the symbol of the anion. Formula unit is considered the basic unit of an ionic compound because ionic compounds do not exist as discrete units. Instead, they exist as crystals, three-dimensional arrays of ions, with cations surrounded by anions and anions surrounded by cations. Chemical formulas for ionic compounds are determined by balancing the positive charge from the cation (s) with the negative charge from the anion (s). A subscript to the right of the ion indicates that more than one of that ion is present in the chemical formula. Some ions are groups of atoms bonded together and having an overall electrical charge. These are called polyatomic ions. Writing formulas with polyatomic ions follows the same rules as with monatomic ions, except that when more than one polyatomic ion is present in a chemical formula, the polyatomic ion is enclosed in parentheses and the subscript is outside the right parenthesis. Ionic compounds typically form between metals and nonmetals or between polyatomic ions. Names of ionic compounds are derived from the names of the ions, with the name of the cation coming first, followed by the name of the anion. If an element can form cations of different charges, there are two alternate systems for indicating the compound’s name. In the Stock system, a roman numeral in parentheses indicates the charge on the cation. An example is the name for FeCl 2, which is iron (II) chloride. In the common system, the suffixes - ous and - ic are used to stand for the lower and higher possible charge of the cation, respectively. These suffixes are attached to a stem representing the element (which frequently comes from the Latin form of the element name). An example is the common name for FeCl 2, which is ferrous chloride. The formula mass of an ionic compound is the sum of the masses of each individual atom in the formula. Care must be taken when calculating formula masses for formulas containing multiple polyatomic ions because the subscript outside the parentheses refers to all the atoms in the polyatomic ion. Additional Exercises What number shell is the valence electron shell of a sodium atom? What number shell is the valence shell of a sodium ion? Explain the difference. What number shell is the valence electron shell of a bromine atom? What number shell is the valence shell of a bromide ion? Explain the difference between these answers and the answers to Exercise 1. What is the electron configuration of each ion? K + Mg 2+ F − S 2− What is the electron configuration of each ion? Li + Ca 2+ Cl − O 2− If a sodium atom were to lose two electrons, what would be the electron configuration of the resulting cation? Considering that electron shells are typically separated by large amounts of energy, use your answer to Exercise 5a to suggest why sodium atoms do not form a 2+ cation. If a chlorine atom were to gain two electrons, what would be the electron configuration of the resulting anion? Considering that electron shells are typically separated by large amounts of energy, use your answer to Exercise 6a to suggest why chlorine atoms do not form a 2− anion. Use Lewis diagrams and arrows to show the electron transfer that occurs during the formation of an ionic compound among Mg atoms and F atoms. (Hint: how many atoms of each will you need?) Use Lewis diagrams and arrows to show the electron transfer that occurs during the formation of an ionic compound among K atoms and O atoms. (Hint: how many atoms of each will you need?) Mercury forms two possible cations—Hg 2+ and Hg 22+, the second of which is actually a two-atom cation with a 2+ charge. Using common names, give the probable names of these ions. What are the chemical formulas of the ionic compounds these ions make with the oxide ion, O 2−? The uranyl ion (UO 22+) is a common water-soluble form of uranium. What is the chemical formula of the ionic compound uranyl nitrate? What is the chemical formula of the ionic compound uranyl phosphate? The formal chemical name of the mineral strengite is iron (III) phosphate dihydrate. What is the chemical formula of strengite? What is the formula mass of strengite? What is the formula mass of MgSO 4 ·7H 2 O? What is the formula mass of CaSO 4 ·½H 2 O? What mass does 20 formula units of NaCl have? What mass does 75 formula units of K 2 SO 4 have? If an atomic mass unit equals 1.66 × 10 −24 g, what is the mass in grams of one formula unit of NaCl? If an atomic mass unit equals 1.66 × 10 −24 g, what is the mass in grams of 5.00 × 10 22 formula units of NaOH? If an atomic mass unit equals 1.66 × 10 −24 g, what is the mass in grams of 3.96 × 10 23 formula units of (NH 4) 2 SO 4? Both tin and lead acquire 2+ or 4+ charges when they become ions. Use the periodic table to explain why this should not surprise you. Which ion would you expect to be larger in size—In 3+ or Tl 3+? Explain. Which ion would you expect to be smaller in size—I − or Br −? Explain. Which ion with a 2+ charge has the following electron configuration? 1 s2 2 s2 2 p6 Which ion with a 3− charge has the following electron configuration? 1 s2 2 s2 2 p6 Answers For sodium, the valence shell is the third shell; for the sodium ion, the valence shell is the second shell because it has lost all its third shell electrons. 1 s2 2 s2 2 p6 3 s2 3 p6 1 s2 2 s2 2 p6 1 s2 2 s2 2 p6 1 s2 2 s2 2 p6 3 s2 3 p6 1 s2 2 s2 2 p5 It probably requires too much energy to form. mercuric and mercurous, respectively HgO and Hg 2 O, respectively FePO 4 ·2H 2 O; 186.86 u 145.16 u 13,070.25 u 3.32 g Both tin and lead have two p electrons and two s electrons in their valence shells. Br − because it is higher up on the periodic table N 3−	msmarco_doc_00_11785073
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s07-02-covalent-compounds-formulas-an.html	Covalent Compounds: Formulas and Names	4.2 Covalent Compounds: Formulas and Names 4.2 Covalent Compounds: Formulas and Names Learning Objectives Example 2 Skill-Building Exercise Example 3 Skill-Building Exercise Note Example 4 Skill-Building Exercise Answers Key Takeaways Exercises Answers	Covalent Compounds: Formulas and Names 4.2 Covalent Compounds: Formulas and Names Learning Objectives Determine the chemical formula of a simple covalent compound from its name. Determine the name of a simple covalent compound from its chemical formula. What elements make covalent bonds? Covalent bonds form when two or more nonmetals combine. For example, both hydrogen and oxygen are nonmetals, and when they combine to make water, they do so by forming covalent bonds. Nonmetal atoms in polyatomic ions are joined by covalent bonds, but the ion as a whole participates in ionic bonding. For example, ammonium chloride has ionic bonds between a polyatomic ion, NH 4+, and Cl − ions, but within the ammonium ion, the nitrogen and hydrogen atoms are connected by covalent bonds: Example 2 Is each compound formed from ionic bonds, covalent bonds, or both? Na 2 O Na 3 PO 4 N 2 O 4 Solution The elements in Na 2 O are a metal and a nonmetal, which form ionic bonds. Because sodium is a metal and we recognize the formula for the phosphate ion (see Table 3.1 "Some Polyatomic Ions" ), we know that this compound is ionic. However, polyatomic ions are held together by covalent bonds, so this compound contains both ionic and covalent bonds. The elements in N 2 O 4 are both nonmetals, rather than a metal and a nonmetal. Therefore, the atoms form covalent bonds. Skill-Building Exercise Is each compound are formed from ionic bonds, covalent bonds, or both? Ba (OH) 2 F 2 PCl 3 The chemical formulas for covalent compounds are referred to as molecular formulas A chemical formula for a covalent compound. because these compounds exist as separate, discrete molecules. Typically, a molecular formula begins with the nonmetal that is closest to the lower left corner of the periodic table, except that hydrogen is almost never written first (H 2 O is the prominent exception). Then the other nonmetal symbols are listed. Numerical subscripts are used if there is more than one of a particular atom. For example, we have already seen CH 4, the molecular formula for methane. Naming binary (two-element) covalent compounds is similar to naming simple ionic compounds. The first element in the formula is simply listed using the name of the element. The second element is named by taking the stem of the element name and adding the suffix - ide. A system of numerical prefixes is used to specify the number of atoms in a molecule. Table 4.1 "Numerical Prefixes for Naming Binary Covalent Compounds" lists these numerical prefixes. Normally, no prefix is added to the first element’s name if there is only one atom of the first element in a molecule. If the second element is oxygen, the trailing vowel is usually omitted from the end of a polysyllabic prefix but not a monosyllabic one (that is, we would say “monoxide” rather than “monooxide” and “trioxide” rather than “troxide”). Table 4.1 Numerical Prefixes for Naming Binary Covalent Compounds Number of Atoms in Compound Prefix on the Name of the Element 1 mono-* 2 di- 3 tri- 4 tetra- 5 penta- 6 hexa- 7 hepta- 8 octa- 9 nona- 10 deca- *This prefix is not used for the first element’s name. Let us practice by naming the compound whose molecular formula is CCl 4. The name begins with the name of the first element—carbon. The second element, chlor ine, becomes chlor ide, and we attach the correct numerical prefix (“tetra-”) to indicate that the molecule contains four chlorine atoms. Putting these pieces together gives the name carbon tetrachloride for this compound. Example 3 Write the molecular formula for each compound. chlorine trifluoride phosphorus pentachloride sulfur dioxide dinitrogen pentoxide Solution If there is no numerical prefix on the first element’s name, we can assume that there is only one atom of that element in a molecule. ClF 3 PCl 5 SO 2 N 2 O 5 (The di - prefix on nitrogen indicates that two nitrogen atoms are present.) Skill-Building Exercise Write the molecular formula for each compound. nitrogen dioxide dioxygen difluoride sulfur hexafluoride selenium monoxide Note Because it is so unreactive, sulfur hexafluoride is used as a spark suppressant in electrical devices such as transformers. Example 4 Write the name for each compound. BrF 5 S 2 F 2 CO Solution bromine pentafluoride disulfur difluoride carbon monoxide Skill-Building Exercise Write the name for each compound. CF 4 SeCl 2 SO 3 For some simple covalent compounds, we use common names rather than systematic names. We have already encountered these compounds, but we list them here explicitly: H 2 O: water NH 3: ammonia CH 4: methane Methane is the simplest organic compound A compound containing carbon atoms. . Organic compounds are compounds with carbon atoms and are named by a separate nomenclature system that we will introduce in Section 4.6 "Introduction to Organic Chemistry". Answers A covalent compound is usually composed of two or more nonmetal elements. It is just like an ionic compound except that the element further down and to the left on the periodic table is listed first and is named with the element name. Name the first element first and then the second element by using the stem of the element name plus the suffix - ide. Use numerical prefixes if there is more than one atom of the first element; always use numerical prefixes for the number of atoms of the second element. Key Takeaways The chemical formula of a simple covalent compound can be determined from its name. The name of a simple covalent compound can be determined from its chemical formula. Exercises Identify whether each compound has covalent bonds. NaI Na 2 CO 3 N 2 O SiO 2 Identify whether each compound has covalent bonds. C 2 H 6 C 6 H 5 Cl KC 2 H 3 O 2 Ca (OH) 2 Identify whether each compound has ionic bonds, covalent bonds, or both. Na 3 PO 4 K 2 O COCl 2 CoCl 2 Identify whether each compound has ionic bonds, covalent bonds, or both. FeCl 3 Fe (NO 3) 3 (NH 2) 2 CO SO 3 Which is the correct molecular formula—H 4 Si or SiH 4? Explain. Which is the correct molecular formula—SF 6 or F 6 S? Explain. Write the name for each covalent compound. SiF 4 NO 2 CS 2 P 2 O 5 Write the name for each covalent compound. CO S 2 O 3 BF 3 GeS 2 Write the formula for each covalent compound. iodine trichloride disulfur dibromide arsenic trioxide xenon hexafluoride Write the formula for each covalent compound. boron trichloride carbon dioxide tetraphosphorus decoxide germanium dichloride Write two covalent compounds that have common rather than systematic names. What is the name of the simplest organic compound? What would its name be if it followed the nomenclature for binary covalent compounds? Answers no yes yes yes both ionic covalent ionic SiH 4; except for water, hydrogen is almost never listed first in a covalent compound. silicon tetrafluoride nitrogen dioxide carbon disulfide diphosphorus pentoxide ICl 3 S 2 Br 2 AsO 3 XeF 6 H 2 O and NH 3 (water and ammonia) (answers will vary)	msmarco_doc_00_11841793
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s08-01-the-law-of-conservation-of-mat.html	The Law of Conservation of Matter	5.1 The Law of Conservation of Matter 5.1 The Law of Conservation of Matter Learning Objectives Answers Key Takeaway Exercises Answer	The Law of Conservation of Matter 5.1 The Law of Conservation of Matter Learning Objectives Correctly define a law as it pertains to science. State the law of conservation of matter. In science, a law A general statement that explains a large number of observations. is a general statement that explains a large number of observations. Before being accepted, a law must be verified many times under many conditions. Laws are therefore considered the highest form of scientific knowledge and are generally thought to be inviolable. Scientific laws form the core of scientific knowledge. One scientific law that provides the foundation for understanding in chemistry is the law of conservation of matter In any given system that is closed to the transfer of matter (in and out), the amount of matter in the system stays constant. . It states that in any given system that is closed to the transfer of matter (in and out), the amount of matter in the system stays constant. A concise way of expressing this law is to say that the amount of matter in a system is conserved. What does this mean for chemistry? In any chemical change, one or more initial substances change into a different substance or substances. Both the initial and final substances are composed of atoms because all matter is composed of atoms. According to the law of conservation of matter, matter is neither created nor destroyed, so we must have the same number and type of atoms after the chemical change as were present before the chemical change. Before looking at explicit examples of the law of conservation of matter, we need to examine the method chemists use to represent chemical changes. Answers The law of conservation of matter states that in any given system that is closed to the transfer of matter, the amount of matter in the system stays constant The law of conservation of matter says that in chemical reactions, the total mass of the products must equal the total mass of the reactants. Key Takeaway The amount of matter in a closed system is conserved. Exercises Express the law of conservation of matter in your own words. Explain why the concept of conservation of matter is considered a scientific law. Answer Matter may not be created or destroyed.	msmarco_doc_00_11849524
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s09-05-mole-mass-and-mass-mass-proble.html	Mole-Mass and Mass-Mass Problems	6.5 Mole-Mass and Mass-Mass Problems 6.5 Mole-Mass and Mass-Mass Problems Learning Objective Example 8 Skill-Building Exercise Example 9 Skill-Building Exercise Answers To Your Health: The Synthesis of Taxol Key Takeaway Exercises Answers	Mole-Mass and Mass-Mass Problems 6.5 Mole-Mass and Mass-Mass Problems Learning Objective Convert from mass or moles of one substance to mass or moles of another substance in a chemical reaction. We have established that a balanced chemical equation is balanced in terms of moles as well as atoms or molecules. We have used balanced equations to set up ratios, now in terms of moles of materials, that we can use as conversion factors to answer stoichiometric questions, such as how many moles of substance A react with so many moles of reactant B. We can extend this technique even further. Recall that we can relate a molar amount to a mass amount using molar mass. We can use that ability to answer stoichiometry questions in terms of the masses of a particular substance, in addition to moles. We do this using the following sequence: Collectively, these conversions are called mole-mass calculations A stoichiometry calculation converting between masses and moles of different substances in a chemical reaction. . As an example, consider the balanced chemical equation Fe2O3 + 3SO3 → Fe2(SO4)3 If we have 3.59 mol of Fe 2 O 3, how many grams of SO 3 can react with it? Using the mole-mass calculation sequence, we can determine the required mass of SO 3 in two steps. First, we construct the appropriate molar ratio, determined from the balanced chemical equation, to calculate the number of moles of SO 3 needed. Then using the molar mass of SO 3 as a conversion factor, we determine the mass that this number of moles of SO 3 has. The first step resembles the exercises we did in Section 6.4 "Mole-Mole Relationships in Chemical Reactions". As usual, we start with the quantity we were given: 3.59 mol Fe 2 O 3 × 3 mol SO 3 1 mol Fe 2 O 3 = 10.77 mol SO 3 The mol Fe 2 O 3 units cancel, leaving mol SO 3 unit. Now, we take this answer and convert it to grams of SO 3, using the molar mass of SO 3 as the conversion factor: 10.77 mol SO 3 × 80 .06 g SO 3 1 mol SO 3 = 862 g SO 3 Our final answer is expressed to three significant figures. Thus, in a two-step process, we find that 862 g of SO 3 will react with 3.59 mol of Fe 2 O 3. Many problems of this type can be answered in this manner. The same two-step problem can also be worked out in a single line, rather than as two separate steps, as follows: We get exactly the same answer when combining all the math steps together as we do when we calculate one step at a time. Example 8 How many grams of CO 2 are produced if 2.09 mol of HCl are reacted according to this balanced chemical equation? CaCO3 + 2HCl → CaCl2 + CO2 + H2O Solution Our strategy will be to convert from moles of HCl to moles of CO 2 and then from moles of CO 2 to grams of CO 2. We will need the molar mass of CO 2, which is 44.01 g/mol. Performing these two conversions in a single-line gives 46.0 g of CO 2: The molar ratio between CO 2 and HCl comes from the balanced chemical equation. Skill-Building Exercise How many grams of glucose (C 6 H 12 O 6) are produced if 17.3 mol of H 2 O are reacted according to this balanced chemical equation? 6CO2 + 6H2O → C6H12O6 + 6O2 It is a small step from mole-mass calculations to mass-mass calculations A stoichiometry calculation converting between the mass of one substance and the mass of a different substance in a chemical reaction. . If we start with a known mass of one substance in a chemical reaction (instead of a known number of moles), we can calculate the corresponding masses of other substances in the reaction. The first step in this case is to convert the known mass into moles, using the substance’s molar mass as the conversion factor. Then—and only then—we use the balanced chemical equation to construct a conversion factor to convert that quantity to moles of another substance, which in turn can be converted to a corresponding mass. Sequentially, the process is as follows: This three-part process can be carried out in three discrete steps or combined into a single calculation that contains three conversion factors. The following example illustrates both techniques. Example 9 Methane can react with elemental chlorine to make carbon tetrachloride (CCl 4 ). The balanced chemical equation is as follows: CH4 + 4Cl2 → CCl4 + 4HCl How many grams of HCl are produced by the reaction of 100.0 g of CH 4? Solution First, let us work the problem in stepwise fashion. We begin by converting the mass of CH 4 to moles of CH 4, using the molar mass of CH 4 (16.05 g/mol) as the conversion factor: 100.0 g CH 4 × 1 mol CH 4 16.05 g CH 4 = 6.231 mol CH 4 Note that we inverted the molar mass so that the gram units cancel, giving us an answer in moles. Next, we use the balanced chemical equation to determine the ratio of moles CH 4 and moles HCl and convert our first result into moles of HCl: 6.231 mol CH 4 × 4 mol HCl 1 mol CH 4 = 24.92 mol HCl Finally, we use the molar mass of HCl (36.46 g/mol) as a conversion factor to calculate the mass of 24.92 mol of HCl: 24.92 mol HCl × 36 .46 g HCl 1 mol HCl = 908.5 g HCl In each step, we have limited the answer to the proper number of significant figures. If desired, we can do all three conversions on a single line: 100.0 g CH 4 × 1 mol CH 4 16.05 g CH 4 × 4 mol HCl 1 mol CH 4 × 36 .46 g HCl 1 mol HCl = 908.7 g HCl This final answer is slightly different from our first answer because only the final answer is restricted to the proper number of significant figures. In the first answer, we limited each intermediate quantity to the proper number of significant figures. As you can see, both answers are essentially the same. Skill-Building Exercise The oxidation of propanal (CH 3 CH 2 CHO) to propionic acid (CH 3 CH 2 COOH) has the following chemical equation: CH3CH2CHO + 2K2Cr2O7 → CH3CH2COOH + other products How many grams of propionic acid are produced by the reaction of 135.8 g of K 2 Cr 2 O 7? Answers mol first substance → mol second substance → mass second substance mass first substance → mol first substance → mol second substance → mass second substance To Your Health: The Synthesis of Taxol Taxol is a powerful anticancer drug that was originally extracted from the Pacific yew tree ( Taxus brevifolia ). As you can see from the accompanying figure, taxol is a very complicated molecule, with a molecular formula of C 47 H 51 NO 14. Isolating taxol from its natural source presents certain challenges, mainly that the Pacific yew is a slow-growing tree, and the equivalent of six trees must be harvested to provide enough taxol to treat a single patient. Although related species of yew trees also produce taxol in small amounts, there is significant interest in synthesizing this complex molecule in the laboratory. After a 20-year effort, two research groups announced the complete laboratory synthesis of taxol in 1994. However, each synthesis required over 30 separate chemical reactions, with an overall efficiency of less than 0.05%. To put this in perspective, to obtain a single 300 mg dose of taxol, you would have to begin with 600 g of starting material. To treat the 26,000 women who are diagnosed with ovarian cancer each year with one dose, almost 16,000 kg (over 17 tons) of starting material must be converted to taxol. Taxol is also used to treat breast cancer, with which 200,000 women in the United States are diagnosed every year. This only increases the amount of starting material needed. Clearly, there is intense interest in increasing the overall efficiency of the taxol synthesis. An improved synthesis not only will be easier but also will produce less waste materials, which will allow more people to take advantage of this potentially life-saving drug. Figure 6.4 The Structure of the Cancer Drug Taxol Because of the complexity of the molecule, hydrogen atoms are not shown, but they are present on every atom to give the atom the correct number of covalent bonds (four bonds for each carbon atom). Key Takeaway A balanced chemical equation can be used to relate masses or moles of different substances in a reaction. Exercises Given the following unbalanced chemical equation, H3PO4 + NaOH → H2O + Na3PO4 what mass of H 2 O is produced by the reaction of 2.35 mol of H 3 PO 4? Given the following unbalanced chemical equation, C2H6 + Br2 → C2H4Br2 + HBr what mass of HBr is produced if 0.884 mol of C 2 H 6 is reacted? Certain fats are used to make soap, the first step being to react the fat with water to make glycerol (also known as glycerin) and compounds called fatty acids. One example is as follows: C 3 H 5 (OOC (CH 2) 14 CH 3) 3 a fat + 3H 2 O → C 3 H 5 (OH) 3 glycerol + 3CH 3 (CH 2) 14 COOH fatty acid How many moles of glycerol can be made from the reaction of 1,000.0 g of C 3 H 5 (OOC (CH 2) 14 CH 3) 3? Photosynthesis in plants leads to the general overall reaction for producing glucose (C 6 H 12 O 6 ): 6CO2 + 6H2O → C6H12O6 + 6O2 How many moles of glucose can be made from the reaction of 544 g of CO 2? Precipitation reactions, in which a solid (called a precipitate) is a product, are commonly used to remove certain ions from solution. One such reaction is as follows: Ba (NO3)2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaNO3(aq) How many grams of Na 2 SO 4 are needed to precipitate all the barium ions produced by 43.9 g of Ba (NO 3) 2? Nitroglycerin [C 3 H 5 (ONO 2) 3] is made by reacting nitric acid (HNO 3) with glycerol [C 3 H 5 (OH) 3] according to this reaction: C3H5(OH)3 + 3HNO3 → C3H5(ONO2)3 + 3H2O If 87.4 g of HNO 3 are reacted with excess glycerol, what mass of nitroglycerin can be made? Antacids are bases that neutralize acids in the digestive tract. Magnesium hydroxide [Mg (OH) 2] is one such antacid. It reacts with hydrochloric acid in the stomach according to the following reaction: Mg (OH)2 + 2HCl → MgCl2 + 2H2O How many grams of HCl can a 200 mg dose of Mg (OH) 2 neutralize? Acid rain is caused by the reaction of nonmetal oxides with water in the atmosphere. One such reaction involves nitrogen dioxide (NO 2) and produces nitric acid (HNO 3 ): 3NO2 + H2O → 2HNO3 + NO If 1.82 × 10 13 g of NO 2 enter the atmosphere every year due to human activities, potentially how many grams of HNO 3 can be produced annually? A simplified version of the processing of iron ore into iron metal is as follows: 2Fe2O3 + 3C → 4Fe + 3CO2 How many grams of C are needed to produce 1.00 × 10 9 g of Fe? The SS Hindenburg contained about 5.33 × 10 5 g of H 2 gas when it burned at Lakehurst, New Jersey, in 1937. The chemical reaction is as follows: 2H2 + O2 → 2H2O How many grams of H 2 O were produced? Answers 127 g 1.236 mol 23.9 g 0.251 g 1.61 × 10 8 g	msmarco_doc_00_11852191
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s11-02-solids-and-liquids.html	Solids and Liquids	8.2 Solids and Liquids 8.2 Solids and Liquids Learning Objective Solids Liquids Gases Example 2 Skill-Building Exercise Answer Looking Closer: Water, the Most Important Liquid Key Takeaway Exercises Answers	Solids and Liquids 8.2 Solids and Liquids Learning Objective Describe the solid and liquid phases. Solids and liquids are collectively called condensed phases because their particles are in virtual contact. The two states share little else, however. Solids In the solid state, the individual particles of a substance are in fixed positions with respect to each other because there is not enough thermal energy to overcome the intermolecular interactions between the particles. As a result, solids have a definite shape and volume. Most solids are hard, but some (like waxes) are relatively soft. Many solids composed of ions can also be quite brittle. Figure 8.7 Crystalline Arrangement Some large crystals look the way they do because of the regular arrangement of atoms (ions) in their crystal structure. © Thinkstock Solids usually have their constituent particles arranged in a regular, three-dimensional array of alternating positive and negative ions called a crystal A regular, three-dimensional array of alternating positive and negative ions. . The effect of this regular arrangement of particles is sometimes visible macroscopically, as shown in Figure 8.7 "Crystalline Arrangement". Some solids, especially those composed of large molecules, cannot easily organize their particles in such regular crystals and exist as amorphous A solid with no regular structure. (literally, “without form”) solids. Glass is one example of an amorphous solid. Liquids If the particles of a substance have enough energy to partially overcome intermolecular interactions, then the particles can move about each other while remaining in contact. This describes the liquid state. In a liquid, the particles are still in close contact, so liquids have a definite volume. However, because the particles can move about each other rather freely, a liquid has no definite shape and takes a shape dictated by its container. Gases If the particles of a substance have enough energy to completely overcome intermolecular interactions, then the particles can separate from each other and move about randomly in space. This describes the gas state, which we will consider further in Section 8.3 "Gases and Pressure". Like liquids, gases have no definite shape, but unlike solids and liquids, gases have no definite volume either. The change from solid to liquid usually does not significantly change the volume of a substance. However, the change from a liquid to a gas significantly increases the volume of a substance, by a factor of 1,000 or more. Figure 8.8 "A Representation of the Solid, Liquid, and Gas States" shows the differences among solids, liquids, and gases at the molecular level, while Table 8.2 "Characteristics of the Three States of Matter" lists the different characteristics of these states. Figure 8.8 A Representation of the Solid, Liquid, and Gas States A solid has definite volume and shape, a liquid has a definite volume but no definite shape, and a gas has neither a definite volume nor shape. Table 8.2 Characteristics of the Three States of Matter Characteristic Solid Liquid Gas shape definite indefinite indefinite volume definite definite indefinite relative intermolecular interaction strength strong moderate weak relative particle positions in contact and fixed in place in contact but not fixed not in contact, random positions Example 2 What state or states of matter does each statement, describe? This state has a definite volume. This state has no definite shape. This state allows the individual particles to move about while remaining in contact. Solution This statement describes either the liquid state or the solid state. This statement describes either the liquid state or the gas state. This statement describes the liquid state. Skill-Building Exercise What state or states of matter does each statement describe? This state has individual particles in a fixed position with regard to each other. This state has individual particles far apart from each other in space. This state has a definite shape. Answer Solids have stronger intermolecular interactions than liquids do. Looking Closer: Water, the Most Important Liquid Earth is the only known body in our solar system that has liquid water existing freely on its surface. That is a good thing because life on Earth would not be possible without the presence of liquid water. Water has several properties that make it a unique substance among substances. It is an excellent solvent; it dissolves many other substances and allows those substances to react when in solution. In fact, water is sometimes called the universal solvent because of this ability. Water has unusually high melting and boiling points (0°C and 100°C, respectively) for such a small molecule. The boiling points for similar-sized molecules, such as methane (BP = −162°C) and ammonia (BP = −33°C), are more than 100° lower. Though a liquid at normal temperatures, water molecules experience a relatively strong intermolecular interaction that allows them to maintain the liquid phase at higher temperatures than expected. Unlike most substances, the solid form of water is less dense than its liquid form, which allows ice to float on water. In colder weather, lakes and rivers freeze from the top, allowing animals and plants to continue to live underneath. Water also requires an unusually large amount of energy to change temperature. While 100 J of energy will change the temperature of 1 g of Fe by 230°C, this same amount of energy will change the temperature of 1 g of H 2 O by only 100°C. Thus, water changes its temperature slowly as heat is added or removed. This has a major impact on weather, as storm systems like hurricanes can be impacted by the amount of heat that ocean water can store. Water’s influence on the world around us is affected by these properties. Isn’t it fascinating that such a small molecule can have such a big impact? Key Takeaway Solids and liquids are phases that have their own unique properties. Exercises What are the general properties of solids? What are the general properties of liquids What are the general properties of gases? What phase or phases have a definite volume? What phase or phases do not have a definite volume? Name a common substance that forms a crystal in its solid state. Name a common substance that forms an amorphous solid in its solid state. Are substances with strong intermolecular interactions likely to be solids at higher or lower temperatures? Explain. Are substances with weak intermolecular interactions likely to be liquids at higher or lower temperatures? Explain. State two similarities between the solid and liquid states. State two differences between the solid and liquid states. If individual particles are moving around with respect to each other, a substance may be in either the _______ or ________ state but probably not in the _______ state. If individual particles are in contact with each other, a substance may be in either the ______ or _______ state but probably not in the ______ state. Answers hard, specific volume and shape, high density, cannot be compressed variable volume and shape, low density, compressible sodium chloride (answers will vary) At higher temperatures, their intermolecular interactions are strong enough to hold the particles in place. high density; definite volume	msmarco_doc_00_11863549
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s13-01-arrhenius-definition-of-acids-.html	Arrhenius Definition of Acids and Bases	10.1 Arrhenius Definition of Acids and Bases 10.1 Arrhenius Definition of Acids and Bases Learning Objective Note Note Example 1 Skill-Building Exercise Example 2 Skill-Building Exercise Note Answers Key Takeaway Exercises Answers	Arrhenius Definition of Acids and Bases 10.1 Arrhenius Definition of Acids and Bases Learning Objective Recognize a compound as an Arrhenius acid or an Arrhenius base. One way to define a class of compounds is by describing the various characteristics its members have in common. In the case of the compounds known as acids, the common characteristics include a sour taste, the ability to change the color of the vegetable dye litmus to red, and the ability to dissolve certain metals and simultaneously produce hydrogen gas. For the compounds called bases, the common characteristics are a slippery texture, a bitter taste, and the ability to change the color of litmus to blue. Acids and bases also react with each other to form compounds generally known as salts. Note Although we include their tastes among the common characteristics of acids and bases, we never advocate tasting an unknown chemical! Chemists prefer, however, to have definitions for acids and bases in chemical terms. The Swedish chemist Svante Arrhenius developed the first chemical definitions of acids and bases in the late 1800s. Arrhenius defined an acid A compound that increases the concentration of hydrogen ion (H +) in aqueous solution. as a compound that increases the concentration of hydrogen ion (H +) in aqueous solution. Many acids are simple compounds that release a hydrogen cation into solution when they dissolve. Similarly, Arrhenius defined a base A compound that increases the concentration of hydroxide ion (OH −) in aqueous solution. as a compound that increases the concentration of hydroxide ion (OH −) in aqueous solution. Many bases are ionic compounds that have the hydroxide ion as their anion, which is released when the base dissolves in water. Many bases and their aqueous solutions are named using the normal rules of ionic compounds that were presented in Chapter 3 "Ionic Bonding and Simple Ionic Compounds", Section 3.4 "Ionic Nomenclature"; that is, they are named as hydroxide compounds. For example, the base sodium hydroxide (NaOH) is both an ionic compound and an aqueous solution. However, aqueous solutions of acids have their own naming rules. The names of binary acids (compounds with hydrogen and one other element in their formula) are based on the root of the name of the other element preceded by the prefix hydro - and followed by the suffix - ic acid. Thus, an aqueous solution of HCl [designated “HCl (aq)”] is called hydrochloric acid, H 2 S (aq) is called hydrosulfuric acid, and so forth. Acids composed of more than two elements (typically hydrogen and oxygen and some other element) have names based on the name of the other element, followed by the suffix - ic acid or -ous acid, depending on the number of oxygen atoms in the acid’s formula. Other prefixes, like per- and hypo-, also appear in the names for some acids. Unfortunately, there is no strict rule for the number of oxygen atoms that are associated with the - ic acid suffix; the names of these acids are best memorized. Table 10.1 "Formulas and Names for Some Acids and Bases" lists some acids and bases and their names. Note that acids have hydrogen written first, as if it were the cation, while most bases have the negative hydroxide ion, if it appears in the formula, written last. Note The name oxygen comes from the Latin meaning “acid producer” because its discoverer, Antoine Lavoisier, thought it was the essential element in acids. Lavoisier was wrong, but it is too late to change the name now. Table 10.1 Formulas and Names for Some Acids and Bases Formula Name Acids HCl (aq) hydrochloric acid HBr (aq) hydrobromic acid HI (aq) hydriodic acid H 2 S (aq) hydrosulfuric acid HC 2 H 3 O 2 (aq) acetic acid HNO 3 (aq) nitric acid HNO 2 (aq) nitrous acid H 2 SO 4 (aq) sulfuric acid H 2 SO 3 (aq) sulfurous acid HClO 3 (aq) chloric acid HClO 4 (aq) perchloric acid HClO 2 (aq) chlorous acid H 3 PO 4 (aq) phosphoric acid H 3 PO 3 (aq) phosphorous acid Bases NaOH (aq) sodium hydroxide KOH (aq) potassium hydroxide Mg (OH) 2 (aq) magnesium hydroxide Ca (OH) 2 (aq) calcium hydroxide NH 3 (aq) ammonia Example 1 Name each substance. HF (aq) Sr (OH) 2 (aq) Solution This acid has only two elements in its formula, so its name includes the hydro - prefix. The stem of the other element’s name, fluorine, is fluor, and we must also include the - ic acid ending. Its name is hydrofluoric acid. This base is named as an ionic compound between the strontium ion and the hydroxide ion: strontium hydroxide. Skill-Building Exercise Name each substance. H 2 Se (aq) Ba (OH) 2 (aq) Notice that one base listed in Table 10.1 "Formulas and Names for Some Acids and Bases" —ammonia—does not have hydroxide as part of its formula. How does this compound increase the amount of hydroxide ion in aqueous solution? Instead of dissociating into hydroxide ions, ammonia molecules react with water molecules by taking a hydrogen ion from the water molecule to produce an ammonium ion and a hydroxide ion: NH3(aq) + H2O (ℓ) → NH4+(aq) + OH−(aq) Because this reaction of ammonia with water causes an increase in the concentration of hydroxide ions in solution, ammonia satisfies the Arrhenius definition of a base. Many other nitrogen-containing compounds are bases because they too react with water to produce hydroxide ions in aqueous solution. As we noted previously, acids and bases react chemically with each other to form salts. A salt is a general chemical term for any ionic compound formed from an acid and a base. In reactions where the acid is a hydrogen ion containing compound and the base is a hydroxide ion containing compound, water is also a product. The general reaction is as follows: acid + base → water + salt The reaction of acid and base to make water and a salt is called neutralization The reaction of acid and base to make water and a salt. . Like any chemical equation, a neutralization chemical equation must be properly balanced. For example, the neutralization reaction between sodium hydroxide and hydrochloric acid is as follows: NaOH (aq) + HCl (aq) → NaCl (aq) + H2O (ℓ) with coefficients all understood to be one. The neutralization reaction between sodium hydroxide and sulfuric acid is as follows: 2NaOH (aq) + H2SO4(aq) → Na2SO4(aq) + 2H2O (ℓ) Once a neutralization reaction is properly balanced, we can use it to perform stoichiometry calculations, such as the ones we practiced in Chapter 5 "Introduction to Chemical Reactions" and Chapter 6 "Quantities in Chemical Reactions". Example 2 Nitric acid [HNO 3 (aq)] can be neutralized by calcium hydroxide [Ca (OH) 2 (aq)]. Write a balanced chemical equation for the reaction between these two compounds and identify the salt it produces. For one reaction, 16.8 g of HNO 3 is present initially. How many grams of Ca (OH) 2 are needed to neutralize that much HNO 3? In a second reaction, 805 mL of 0.672 M Ca (OH) 2 is present initially. What volume of 0.432 M HNO 3 solution is necessary to neutralize the Ca (OH) 2 solution? Solution Because there are two OH − ions in the formula for Ca (OH) 2, we need two moles of HNO 3 to provide H + ions. The balanced chemical equation is as follows: Ca (OH)2(aq) + 2HNO3(aq) → Ca (NO3)2(aq) + 2H2O (ℓ) The salt formed is calcium nitrate. This calculation is much like the calculations we did in Chapter 6 "Quantities in Chemical Reactions". First we convert the mass of HNO 3 to moles using its molar mass of 1.01 + 14.00 + 3 (16.00) = 63.01 g/mol; then we use the balanced chemical equation to determine the related number of moles of Ca (OH) 2 needed to neutralize it; and then we convert that number of moles of Ca (OH) 2 to the mass of Ca (OH) 2 using its molar mass of 40.08 + 2 (1.01) + 2 (16.00) = 74.10 g/mol. 16.8 g HNO 3 × 1 mol HNO 3 63.01 g HNO 3 × 1 mol Ca (OH) 2 2 mol HNO 3 × 74.10 g Ca (OH) 2 1 mol Ca (OH) 2 = 9.88 g Ca (OH) 2 needed Having concentration information allows us to employ the skills we developed in Chapter 9 "Solutions". First, we use the concentration and volume data to determine the number of moles of Ca (OH) 2 present. Recognizing that 805 mL = 0.805 L, 0.672 M Ca (OH) 2 = mol Ca (OH) 2 0.805 L soln (0.672 M CaOH)2 × (0.805 L soln) = mol Ca (OH)2 = 0.541 mol Ca (OH)2 We combine this information with the proper ratio from the balanced chemical equation to determine the number of moles of HNO 3 needed: 0.541 mol Ca (OH) 2 × 2 mol HNO 3 1 mol Ca (OH) 2 = 1.08 mol HNO 3 Now, using the definition of molarity one more time, we determine the volume of acid solution needed: 0.432 M HNO 3 = 1.08 mol HNO 3 volume of HNO 3 volume of HNO 3 = 1.08 mol HNO 3 0.432 M HNO 3 = 2.50 L = 2 .50 × 10 3 mL HNO 3 Skill-Building Exercise Hydrocyanic acid [HCN (aq)] can be neutralized by potassium hydroxide [KOH (aq)]. Write a balanced chemical equation for the reaction between these two compounds and identify the salt it produces. For one reaction, 37.5 g of HCN is present initially. How many grams of KOH are needed to neutralize that much HCN? In a second reaction, 43.0 mL of 0.0663 M KOH is present initially. What volume of 0.107 M HCN solution is necessary to neutralize the KOH solution? Note Hydrocyanic acid (HCN) is one exception to the acid-naming rules that specify using the prefix hydro- for binary acids (acids composed of hydrogen and only one other element). Answers Arrhenius acid: a compound that increases the concentration of hydrogen ion (H +) in aqueous solution; Arrhenius base: a compound that increases the concentration of hydroxide ion (OH −) in aqueous solution. the reaction of an acid and a base Key Takeaway An Arrhenius acid increases the H + ion concentration in water, while an Arrhenius base increases the OH − ion concentration in water. Exercises Give two examples of Arrhenius acids. Give two examples of Arrhenius bases. List the general properties of acids. List the general properties of bases. Name each compound. HBr (aq) Ca (OH) 2 (aq) HNO 3 (aq) Fe (OH) 3 (aq) Name each compound. HI (aq) Cu (OH) 2 (aq) H 3 PO 4 (aq) CsOH (aq) Propose a name for water (H 2 O) using the rules for naming acids. Propose a name for hydrogen peroxide (H 2 O 2) using the rules for naming acids. Write a balanced chemical equation for the neutralization of Ba (OH) 2 (aq) with HNO 3 (aq). Write a balanced chemical equation for the neutralization of H 2 SO 4 (aq) with Cr (OH) 3 (aq). How many moles of sodium hydroxide (NaOH) are needed to neutralize 0.844 mol of acetic acid (HC 2 H 3 O 2 )? (Hint: begin by writing a balanced chemical equation for the process.) How many moles of perchloric acid (HClO 4) are needed to neutralize 0.052 mol of calcium hydroxide [Ca (OH) 2 ]? (Hint: begin by writing a balanced chemical equation for the process.) Hydrazoic acid (HN 3) can be neutralized by a base. Write the balanced chemical equation for the reaction between hydrazoic acid and calcium hydroxide. How many milliliters of 0.0245 M Ca (OH) 2 are needed to neutralize 0.564 g of HN 3? Citric acid (H 3 C 6 H 5 O 7) has three hydrogen atoms that can form hydrogen ions in solution. Write the balanced chemical equation for the reaction between citric acid and sodium hydroxide. If an orange contains 0.0675 g of H 3 C 6 H 5 O 7, how many milliliters of 0.00332 M NaOH solution are needed to neutralize the acid? Magnesium hydroxide [Mg (OH) 2] is an ingredient in some antacids. How many grams of Mg (OH) 2 are needed to neutralize the acid in 158 mL of 0.106 M HCl (aq)? It might help to write the balanced chemical equation first. Aluminum hydroxide [Al (OH) 3] is an ingredient in some antacids. How many grams of Al (OH) 3 are needed to neutralize the acid in 96.5 mL of 0.556 M H 2 SO 4 (aq)? It might help to write the balanced chemical equation first. Answers HCl and HNO 3 (answers will vary) sour taste, react with metals, react with bases, and turn litmus red hydrobromic acid calcium hydroxide nitric acid iron (III) hydroxide perhaps hydroxic acid 2HNO 3 (aq) + Ba (OH) 2 (aq) → Ba (NO 3) 2 (aq) + 2H 2 O 0.844 mol 2HN 3 (aq) + Ca (OH) 2 → Ca (N 3) 2 + 2H 2 O 268 mL	msmarco_doc_00_11871504
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s16-unsaturated-and-aromatic-hydro.html	Unsaturated and Aromatic Hydrocarbons	Chapter 13 Unsaturated and Aromatic Hydrocarbons Chapter 13 Unsaturated and Aromatic Hydrocarbons Opening Essay 13.1 Alkenes: Structures and Names Learning Objective Note Example 1 Skill-Building Exercise Example 2 Skill-Building Exercise Answers Exercises Answers 13.2 Cis-Trans Isomers (Geometric Isomers) Learning Objectives Example 3 Skill-Building Exercise Answers Exercises Answer 13.3 Physical Properties of Alkenes Learning Objective Looking Closer: Environmental Note Answers Exercises Answer 13.4 Chemical Properties of Alkenes Learning Objective Example 4 Skill-Building Exercise Answers Exercises Answer 13.5 Polymers Learning Objective The Production of Polyethylene Note Medical Uses of Polymers Answers Key Takeaway Exercises Answer 13.6 Alkynes Learning Objectives Note Answers Exercises Answers 13.7 Aromatic Compounds: Benzene Learning Objective Note To Your Health: Benzene and Us Answers Exercises Answer 13.8 Structure and Nomenclature of Aromatic Compounds Learning Objectives Example 5 Skill-Building Exercise Example 6 Note Skill-Building Exercise Polycyclic Aromatic Hydrocarbons To Your Health: Polycyclic Aromatic Hydrocarbons and Cancer Biologically Important Compounds with Benzene Rings Note Answers Key Takeaway Exercises Answers 13.9 End-of-Chapter Material Chapter Summary Additional Exercises Answers	Unsaturated and Aromatic Hydrocarbons Chapter 13 Unsaturated and Aromatic Hydrocarbons Opening Essay Our modern society is based to a large degree on the chemicals we discuss in this chapter. Most are made from petroleum. In Chapter 12 "Organic Chemistry: Alkanes and Halogenated Hydrocarbons" we noted that alkanes—saturated hydrocarbons—have relatively few important chemical properties other than that they undergo combustion and react with halogens. Unsaturated hydrocarbons—hydrocarbons with double or triple bonds—on the other hand, are quite reactive. In fact, they serve as building blocks for many familiar plastics—polyethylene, vinyl plastics, acrylics—and other important synthetic materials (e.g., alcohols, antifreeze, and detergents). Aromatic hydrocarbons have formulas that can be drawn as cyclic alkenes, making them appear unsaturated, but their structure and properties are generally quite different, so they are not considered to be alkenes. Aromatic compounds serve as the basis for many drugs, antiseptics, explosives, solvents, and plastics (e.g., polyesters and polystyrene). The two simplest unsaturated compounds—ethylene (ethene) and acetylene (ethyne)—were once used as anesthetics and were introduced to the medical field in 1924. However, it was discovered that acetylene forms explosive mixtures with air, so its medical use was abandoned in 1925. Ethylene was thought to be safer, but it too was implicated in numerous lethal fires and explosions during anesthesia. Even so, it remained an important anesthetic into the 1960s, when it was replaced by nonflammable anesthetics such as halothane (CHBrClCF 3 ). 13.1 Alkenes: Structures and Names Learning Objective Name alkenes given formulas and write formulas for alkenes given names. As we noted in Chapter 4 "Covalent Bonding and Simple Molecular Compounds", alkenes A hydrocarbon with one or more carbon–carbon double bonds. are hydrocarbons with carbon-to-carbon double bonds (R 2 C=CR 2) and alkynes A hydrocarbon with a carbon–carbon triple bond. are hydrocarbons with carbon-to-carbon triple bonds (R–C≡C–R). Collectively, they are called unsaturated hydrocarbons An alkene or alkyne having one or more multiple (double or triple) bonds between carbon atoms. because they have fewer hydrogen atoms than does an alkane with the same number of carbon atoms, as is indicated in the following general formulas: Some representative alkenes—their names, structures, and physical properties—are given in Table 13.1 "Physical Properties of Some Selected Alkenes". Table 13.1 Physical Properties of Some Selected Alkenes IUPAC Name Molecular Formula Condensed Structural Formula Melting Point (°C) Boiling Point (°C) ethene C 2 H 4 CH 2 =CH 2 –169 –104 propene C 3 H 6 CH 2 =CHCH 3 –185 –47 1-butene C 4 H 8 CH 2 =CHCH 2 CH 3 –185 –6 1-pentene C 5 H 10 CH 2 =CH (CH 2) 2 CH 3 –138 30 1-hexene C 6 H 12 CH 2 =CH (CH 2) 3 CH 3 –140 63 1-heptene C 7 H 14 CH 2 =CH (CH 2) 4 CH 3 –119 94 1-octene C 8 H 16 CH 2 =CH (CH 2) 5 CH 3 –102 121 We used only condensed structural formulas in Table 13.1 "Physical Properties of Some Selected Alkenes". Thus, CH 2 =CH 2 stands for The double bond is shared by the two carbon atoms and does not involve the hydrogen atoms, although the condensed formula does not make this point obvious. Note that the molecular formula for ethene is C 2 H 4, whereas that for ethane is C 2 H 6. The first two alkenes in Table 13.1 "Physical Properties of Some Selected Alkenes" —ethene and propene ( Figure 13.1 "Ethene and Propene" )—are most often called by their common names—ethylene and propylene, respectively. Ethylene is a major commercial chemical. The US chemical industry produces about 25 billion kilograms of ethylene annually, more than any other synthetic organic chemical. More than half of this ethylene goes into the manufacture of polyethylene, one of the most familiar plastics. (For more information about polymers and plastics, see Section 13.5 "Polymers" .) Propylene is also an important industrial chemical. It is converted to plastics, isopropyl alcohol, and a variety of other products. (For more information about alcohols, see Chapter 14 "Organic Compounds of Oxygen", Section 14.2 "Alcohols: Nomenclature and Classification" .) Figure 13.1 Ethene and Propene The ball-and-spring models of ethene/ethylene (a) and propene/propylene (b) show their respective shapes, especially bond angles. Note Although there is only one alkene with the formula C 2 H 4 (ethene) and only one with the formula C 3 H 6 (propene), there are several alkenes with the formula C 4 H 8. Section 13.2 "Cis-Trans Isomers (Geometric Isomers)" begins a discussion of butenes. Here are some basic rules for naming alkenes from the International Union of Pure and Applied Chemistry (IUPAC): The longest chain of carbon atoms containing the double bond is considered the parent chain. It is named using the same stem as the alkane having the same number of carbon atoms but ends in - ene to identify it as an alkene. Thus the compound CH 2 =CHCH 3 is propene. If there are four or more carbon atoms in a chain, we must indicate the position of the double bond. The carbons atoms are numbered so that the first of the two that are doubly bonded is given the lower of the two possible numbers. The compound CH 3 CH=CHCH 2 CH 3, for example, has the double bond between the second and third carbon atoms. Its name is 2-pentene (not 3-pentene). Substituent groups are named as with alkanes, and their position is indicated by a number. Thus, is 5-methyl-2-hexene. Note that the numbering of the parent chain is always done in such a way as to give the double bond the lowest number, even if that causes a substituent to have a higher number. The double bond always has priority in numbering. Example 1 Name each compound. Solution The longest chain containing the double bond has five carbon atoms, so the compound is a pentene (rule 1). To give the first carbon atom of the double bond the lowest number (rule 2), we number from the left, so the compound is a 2-pentene. There is a methyl group on the fourth carbon atom (rule 3), so the compound’s name is 4-methyl-2-pentene. The longest chain containing the double bond has four carbon atoms, so the parent compound is a butene (rule 1). (The longest chain overall has five carbon atoms, but it does not contain the double bond, so the parent name is not pentene .) To give the first carbon atom of the double bond the lowest number (rule 2), we number from the left, so the compound is a 1-butene. There is an ethyl group on the second carbon atom (rule 3), so the compound’s name is 2-ethyl-1-butene. Skill-Building Exercise Name each compound. CH 3 CH 2 CH 2 CH 2 CH 2 CH=CHCH 3 Just as there are cycloalkanes, there are cycloalkenes. These compounds are named like alkenes, but with the prefix cyclo - attached to the beginning of the parent alkene name. Example 2 Draw the structure for each compound. 3-methyl-2-pentene cyclohexene Solution First write the parent chain of five carbon atoms: C–C–C–C–C. Then add the double bond between the second and third carbon atoms: Now place the methyl group on the third carbon atom and add enough hydrogen atoms to give each carbon atom a total of four bonds. First, consider what each of the three parts of the name means. Cyclo means a ring compound, hex means 6 carbon atoms, and - ene means a double bond. Skill-Building Exercise Draw the structure for each compound. 2-ethyl-1-hexene cyclopentene Answers Unsaturated hydrocarbons have double or triple bonds and are quite reactive; saturated hydrocarbons have only single bonds and are rather unreactive. An alkene has a double bond; an alkane has single bonds only. saturated; alkane unsaturated; alkyne unsaturated; alkene Key Takeaway Alkenes are hydrocarbons with a carbon-to-carbon double bond. Exercises Draw the structure for each compound. 2-methyl-2-pentene 2,3-dimethyl-1-butene cyclohexene Draw the structure for each compound. 5-methyl-1-hexene 3-ethyl-2-pentene 4-methyl-2-hexene Name each compound according to the IUPAC system. Name each compound according to the IUPAC system. Answers 2-methyl-2-pentene 3-methyl-2-heptene 2,5-dimethyl-2-hexene 13.2 Cis-Trans Isomers (Geometric Isomers) Learning Objectives Recognize that alkenes that can exist as cis-trans isomers. Classify isomers as cis or trans. Draw structures for cis-trans isomers given their names. As noted in Chapter 12 "Organic Chemistry: Alkanes and Halogenated Hydrocarbons", there is free rotation about the carbon-to-carbon single bonds (C–C) in alkanes. In contrast, the structure of alkenes requires that the carbon atoms of a double bond and the two atoms bonded to each carbon atom all lie in a single plane, and that each doubly bonded carbon atom lies in the center of a triangle. This part of the molecule’s structure is rigid; rotation about doubly bonded carbon atoms is not possible without rupturing the bond. Look at the two chlorinated hydrocarbons in Figure 13.2 "Rotation about Bonds". Figure 13.2 Rotation about Bonds In 1,2-dichloroethane (a), free rotation about the C–C bond allows the two structures to be interconverted by a twist of one end relative to the other. In 1,2-dichloroethene (b), restricted rotation about the double bond means that the relative positions of substituent groups above or below the double bond are significant. In 1,2-dichloroethane (part (a) of Figure 13.2 "Rotation about Bonds" ), there is free rotation about the C–C bond. The two models shown represent exactly the same molecule; they are not isomers. You can draw structural formulas that look different, but if you bear in mind the possibility of this free rotation about single bonds, you should recognize that these two structures represent the same molecule: In 1,2-dichloroethene (part (b) of Figure 13.2 "Rotation about Bonds" ), however, restricted rotation about the double bond means that the relative positions of substituent groups above or below the double bond become significant. This leads to a special kind of isomerism. The isomer in which the two chlorine (Cl) atoms lie on the same side of the molecule is called the cis isomer An isomer in which two substituent groups are attached on the same side of a double bond or ring in an organic molecule. (Latin cis, meaning “on this side”) and is named cis-1,2-dichloroethene. The isomer with the two Cl atoms on opposite sides of the molecule is the trans isomer An isomer in which two substituent groups are attached to opposite sides of a double bond or ring in a molecule. (Latin trans, meaning “across”) and is named trans -1,2-dichloroethene. These two compounds are cis-trans isomers (or geometric isomers) Isomers that have different configurations because of the presence of a rigid structure such as a double bond or ring. , compounds that have different configurations (groups permanently in different places in space) because of the presence of a rigid structure in their molecule. Consider the alkene with the condensed structural formula CH 3 CH=CHCH 3. We could name it 2-butene, but there are actually two such compounds; the double bond results in cis-trans isomerism ( Figure 13.3 "Ball-and-Spring Models of (a) Cis-2-Butene and (b) Trans-2-Butene" ). Figure 13.3 Ball-and-Spring Models of (a) Cis-2-Butene and (b) Trans-2-Butene Cis-trans isomers have different physical, chemical, and physiological properties. Cis -2-butene has both methyl groups on the same side of the molecule. Trans -2-butene has the methyl groups on opposite sides of the molecule. Their structural formulas are as follows: Note, however, that the presence of a double bond does not necessarily lead to cis-trans isomerism. We can draw two seemingly different propenes: However, these two structures are not really different from each other. If you could pick up either molecule from the page and flip it over top to bottom, you would see that the two formulas are identical. Thus there are two requirements for cis-trans isomerism: Rotation must be restricted in the molecule. There must be two nonidentical groups on each doubly bonded carbon atom. In these propene structures, the second requirement for cis-trans isomerism is not fulfilled. One of the doubly bonded carbon atoms does have two different groups attached, but the rules require that both carbon atoms have two different groups. In general, the following statements hold true in cis-trans isomerism: Alkenes with a C=CH 2 unit do not exist as cis-trans isomers. Alkenes with a C=CR 2 unit, where the two R groups are the same, do not exist as cis-trans isomers. Alkenes of the type R–CH=CH–R can exist as cis and trans isomers; cis if the two R groups are on the same side of the carbon-to-carbon double bond, and trans if the two R groups are on opposite sides of the carbon-to-carbon double bond. Cis-trans isomerism also occurs in cyclic compounds. In ring structures, groups are unable to rotate about any of the ring carbon–carbon bonds. Therefore, groups can be either on the same side of the ring (cis) or on opposite sides of the ring (trans). For our purposes here, we represent all cycloalkanes as planar structures, and we indicate the positions of the groups, either above or below the plane of the ring. Example 3 Which compounds can exist as cis-trans (geometric) isomers? Draw them. CHCl=CHBr CH 2 =CBrCH 3 (CH 3) 2 C=CHCH 2 CH 3 CH 3 CH=CHCH 2 CH 3 Solution All four structures have a double bond and thus meet rule 1 for cis-trans isomerism. This compound meets rule 2; it has two nonidentical groups on each carbon atom (H and Cl on one and H and Br on the other). It exists as both cis and trans isomers: This compound has two hydrogen atoms on one of its doubly bonded carbon atoms; it fails rule 2 and does not exist as cis and trans isomers. This compound has two methyl (CH 3) groups on one of its doubly bonded carbon atoms. It fails rule 2 and does not exist as cis and trans isomers. This compound meets rule 2; it has two nonidentical groups on each carbon atom and exists as both cis and trans isomers: Skill-Building Exercise Which compounds can exist as cis-trans isomers? Draw them. CH 2 =CHCH 2 CH 2 CH 3 CH 3 CH=CHCH 2 CH 3 CH 3 CH 2 CH=CHCH 2 CH 3 Answers Cis-trans isomers are compounds that have different configurations (groups permanently in different places in space) because of the presence of a rigid structure in their molecule. Alkenes and cyclic compounds can exhibit cis-trans isomerism. trans cis cis neither Key Takeaway Cis-trans (geometric) isomerism exists when there is restricted rotation in a molecule and there are two nonidentical groups on each doubly bonded carbon atom. Exercises Draw the structures of the cis-trans isomers for each compound. Label them cis and trans. If no cis-trans isomers exist, write none. 2-bromo-2-pentene 3-heptene 4-methyl-2-pentene 1,1-dibromo-1-butene 2-butenoic acid (CH 3 CH=CHCOOH) Draw the structures of the cis-trans isomers for each compound. Label them cis and trans. If no cis-trans isomers exist, write none. 2,3-dimethyl-2-pentene 1,1-dimethyl-2-ethylcyclopropane 1,2-dimethylcyclohexane 5-methyl-2-hexene 1,2,3-trimethylcyclopropane Answer none none 13.3 Physical Properties of Alkenes Learning Objective Identify the physical properties of alkenes and describe trends in these properties. The physical properties of alkenes are similar to those of the alkanes. Table 13.1 "Physical Properties of Some Selected Alkenes" (in Section 13.1 "Alkenes: Structures and Names") shows that the boiling points of straight-chain alkenes increase with increasing molar mass, just as with alkanes. For molecules with the same number of carbon atoms and the same general shape, the boiling points usually differ only slightly, just as we would expect for substances whose molar mass differs by only 2 u (equivalent to two hydrogen atoms). Like other hydrocarbons, the alkenes are insoluble in water but soluble in organic solvents. Looking Closer: Environmental Note Alkenes occur widely in nature. Ripening fruits and vegetables give off ethylene, which triggers further ripening. Fruit processors artificially introduce ethylene to hasten the ripening process; exposure to as little as 0.1 mg of ethylene for 24 h can ripen 1 kg of tomatoes. Unfortunately, this process does not exactly duplicate the ripening process, and tomatoes picked green and treated this way don’t taste much like vine-ripened tomatoes fresh from the garden. Other alkenes that occur in nature include 1-octene, a constituent of lemon oil, and octadecene (C 18 H 36) found in fish liver. Dienes (two double bonds) and polyenes (three or more double bonds) are also common. Butadiene (CH 2 =CHCH=CH 2) is found in coffee. Lycopene and the carotenes are isomeric polyenes (C 40 H 56) that give the attractive red, orange, and yellow colors to watermelons, tomatoes, carrots, and other fruits and vegetables. Vitamin A, essential to good vision, is derived from a carotene. The world would be a much less colorful place without alkenes. The bright red color of tomatoes is due to lycopene—a polyene. © Thinkstock Answers Alkenes have physical properties (low boiling points, insoluble in water) quite similar to those of their corresponding alkanes. ethene < propene < 1-butene < 1-hexene Key Takeaway The physical properties of alkenes are much like those of the alkanes: their boiling points increase with increasing molar mass, and they are insoluble in water. Exercises Without referring to a table or other reference, predict which member of each pair has the higher boiling point. 1-pentene or 1-butene 3-heptene or 3-nonene Which is a good solvent for cyclohexene, pentane or water? Answer 1-pentene 3-nonene 13.4 Chemical Properties of Alkenes Learning Objective Write equations for the addition reactions of alkenes with hydrogen, halogens, and water. Alkenes are valued mainly for addition reactions A reaction in which substituent groups join to hydrocarbon molecules at points of unsaturation—the double or triple bonds. , in which one of the bonds in the double bond is broken. Each of the carbon atoms in the bond can then attach another atom or group while remaining joined to each other by a single bond. Perhaps the simplest addition reaction is hydrogenation A reaction in which hydrogen gas reacts at a carbon-to-carbon double or triple bond or a carbon-to-oxygen double bond to add hydrogen atoms to carbon atoms. —a reaction with hydrogen (H 2) in the presence of a catalyst such as nickel (Ni) or platinum (Pt). The product is an alkane having the same carbon skeleton as the alkene. (The use of hydrogenation to convert unsaturated vegetable oils to saturated fats is discussed in Chapter 17 "Lipids", Section 17.2 "Fats and Oils" .) Alkenes also readily undergo halogenation A reaction in which a halogen reacts at a carbon-to-carbon double or triple bond to add halogen atoms to carbon atoms. —the addition of halogens. Indeed, the reaction with bromine (Br 2) can be used to test for alkenes. Bromine solutions are brownish red. When we add a Br 2 solution to an alkene, the color of the solution disappears because the alkene reacts with the bromine: Another important addition reaction is that between an alkene and water to form an alcohol. This reaction, called hydration The addition of water to a substance; in organic chemistry, the addition of water across the carbon-to-carbon double bond of an alkene or the carbon-to-oxygen double bond of an aldehyde or ketone. , requires a catalyst—usually a strong acid, such as sulfuric acid (H 2 SO 4 ): The hydration reaction is discussed further in Chapter 14 "Organic Compounds of Oxygen", Section 14.4 "Reactions That Form Alcohols", where we deal with this reaction in the synthesis of alcohols. Example 4 Write the equation for the reaction between CH 3 CH=CHCH 3 and each substance. H 2 (Ni catalyst) Br 2 H 2 O (H 2 SO 4 catalyst) Solution In each reaction, the reagent adds across the double bond. Skill-Building Exercise Write the equation for each reaction. CH 3 CH 2 CH=CH 2 with H 2 (Ni catalyst) CH 3 CH=CH 2 with Cl 2 CH 3 CH 2 CH=CHCH 2 CH 3 with H 2 O (H 2 SO 4 catalyst) Answers Alkenes undergo addition reactions; alkanes do not. Both burn. C 12 H 24 Br 2 Key Takeaway Alkenes undergo addition reactions, adding such substances as hydrogen, bromine, and water across the carbon-to-carbon double bond. Exercises Complete each equation. (CH 3) 2 C=CH 2 + Br 2 → CH 2 =C (CH 3 )CH 2 CH 3 + H 2 → Ni Complete each equation. CH 2 =CHCH=CH 2 + 2H 2 → Ni (CH 3) 2 C=C (CH 3) 2 + H 2 O → H 2 SO 4 Answer (CH 3) 2 CBrCH 2 Br CH 3 CH (CH 3 )CH 2 CH 3 13.5 Polymers Learning Objective Draw structures for monomers that can undergo addition polymerization and for four-monomer-unit sections of an addition polymer. The most important commercial reactions of alkenes are polymerizations, reactions in which small molecules, referred to in general as monomers A small molecule that can be combined with other small molecules to make polymers. (from the Greek monos, meaning “one,” and meros, meaning “parts”), are assembled into giant molecules referred to as polymers A giant molecule formed by the combination of monomers in a repeating manner. (from the Greek poly, meaning “many,” and meros, meaning “parts”). A polymer is as different from its monomer as a long strand of spaghetti is from a tiny speck of flour. For example, polyethylene, the familiar waxy material used to make plastic bags, is made from the monomer ethylene—a gas. The Production of Polyethylene (click to see video) Polyethylene pellets are melted, formed into a giant bubble, and then made into a film that is used in packaging, consumer products, and food services. There are two general types of polymerization reactions: addition polymerization and condensation polymerization. (For more information about condensation polymerization, see Chapter 15 "Organic Acids and Bases and Some of Their Derivatives", Section 15.8 "Preparation of Esters" .) In addition polymerization A reaction in which monomers add to one another to produce a polymeric product that contains all the atoms of the starting monomers. , the monomers add to one another in such a way that the polymer contains all the atoms of the starting monomers. Ethylene molecules are joined together in long chains. The polymerization can be represented by the reaction of a few monomer units: The bond lines extending at the ends in the formula of the product indicate that the structure extends for many units in each direction. Notice that all the atoms—two carbon atoms and four hydrogen atoms—of each monomer molecule are incorporated into the polymer structure. Because displays such as the one above are cumbersome, the polymerization is often abbreviated as follows: n CH 2 =CH 2 → [ CH 2 CH 2 ] n Note Many natural materials—such as proteins, cellulose and starch, and complex silicate minerals—are polymers. (For more information about proteins and cellulose/starch, see Chapter 18 "Amino Acids, Proteins, and Enzymes", Section 18.4 "Proteins", and Chapter 16 "Carbohydrates", Section 16.7 "Polysaccharides", respectively.) Artificial fibers, films, plastics, semisolid resins, and rubbers are also polymers. More than half the compounds produced by the chemical industry are synthetic polymers. Some common addition polymers are listed in Table 13.2 "Some Addition Polymers". Note that all the monomers have carbon-to-carbon double bonds. Many polymers are mundane (e.g., plastic bags, food wrap, toys, and tableware), but there are also polymers that conduct electricity, have amazing adhesive properties, or are stronger than steel but much lighter in weight. Table 13.2 Some Addition Polymers Monomer Polymer Polymer Name Some Uses CH 2 =CH 2 ~CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 ~ polyethylene plastic bags, bottles, toys, electrical insulation CH 2 =CHCH 3 polypropylene carpeting, bottles, luggage, exercise clothing CH 2 =CHCl polyvinyl chloride bags for intravenous solutions, pipes, tubing, floor coverings CF 2 =CF 2 ~CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 ~ polytetrafluoroethylene nonstick coatings, electrical insulation Medical Uses of Polymers An interesting use of polymers is the replacement of diseased, worn out, or missing parts in the body. For example, about a 250,000 hip joints and 500,000 knees are replaced in US hospitals each year. The artificial ball-and-socket hip joints are made of a special steel (the ball) and plastic (the socket). People crippled by arthritis or injuries gain freedom of movement and relief from pain. Patients with heart and circulatory problems can be helped by replacing worn out heart valves with parts based on synthetic polymers. These are only a few of the many biomedical uses of polymers. Figure 13.4 Hip Joint Replacement Synthetic polymers are an important part of a hip joint replacement. The hip is much like a ball-and-socket joint, and total hip replacements mimic this with a metal ball that fits in a plastic cup. Answers Monomers are small molecules that can be assembled into giant molecules referred to as polymers, which are much larger than the molecules we discussed earlier in this chapter. In addition polymerization, the monomers add to one another in such a way that the polymer contains all the atoms of the starting monomers. C 350 H 525 Cl 175 Key Takeaway Molecules having carbon-to-carbon double bonds can undergo addition polymerization. Exercises Write the condensed structural formula of the monomer from which Saran is formed. A segment of the Saran molecule has the following structure: CH 2 CCl 2 CH 2 CCl 2 CH 2 CCl 2 CH 2 CCl 2. Write the condensed structural formula for the section of a molecule formed from four units of the monomer CH 2 =CHF. Answer H 2 C=CCl 2 13.6 Alkynes Learning Objectives Describe the general physical and chemical properties of alkynes. Name alkynes given formulas and write formulas for alkynes given names. The simplest alkyne—a hydrocarbon with carbon-to-carbon triple bond—has the molecular formula C 2 H 2 and is known by its common name—acetylene ( Figure 13.5 "Ball-and-Spring Model of Acetylene" ). Its structure is H–C≡C–H. Figure 13.5 Ball-and-Spring Model of Acetylene Acetylene (ethyne) is the simplest member of the alkyne family. Note Acetylene is used in oxyacetylene torches for cutting and welding metals. The flame from such a torch can be very hot. Most acetylene, however, is converted to chemical intermediates that are used to make vinyl and acrylic plastics, fibers, resins, and a variety of other products. Alkynes are similar to alkenes in both physical and chemical properties. For example, alkynes undergo many of the typical addition reactions of alkenes. The International Union of Pure and Applied Chemistry (IUPAC) names for alkynes parallel those of alkenes, except that the family ending is - yne rather than - ene. The IUPAC name for acetylene is ethyne. The names of other alkynes are illustrated in the following exercises. Answers Alkenes have double bonds; alkynes have triple bonds. Both undergo addition reactions. 4-methyl-1-pentyne No; a triply bonded carbon atom can form only one other bond. It would have to have two groups attached to show cis-trans isomerism. Key Takeaway Alkynes are hydrocarbons with carbon-to-carbon triple bonds and properties much like those of alkenes. Exercises Draw the structure for each compound. acetylene 3-methyl-1-hexyne Draw the structure for each compound. 4-methyl-2-hexyne 3-octyne Name each alkyne. CH 3 CH 2 CH 2 C≡CH CH 3 CH 2 CH 2 C≡CCH 3 Answers H–C≡C–H 1-pentyne 2-hexyne 13.7 Aromatic Compounds: Benzene Learning Objective Describe the bonding in benzene and the way typical reactions of benzene differ from those of the alkenes. Next we consider a class of hydrocarbons with molecular formulas like those of unsaturated hydrocarbons, but which, unlike the alkenes, do not readily undergo addition reactions. These compounds comprise a distinct class, called aromatic hydrocarbons A hydrocarbon with a benzene-like structure. , with unique structures and properties. We start with the simplest of these compounds. Benzene (C 6 H 6) is of great commercial importance, but it also has noteworthy health effects (see “To Your Health: Benzene and Us”). The formula C 6 H 6 seems to indicate that benzene has a high degree of unsaturation. (Hexane, the saturated hydrocarbon with six carbon atoms has the formula C 6 H 14 —eight more hydrogen atoms than benzene.) However, despite the seeming low level of saturation, benzene is rather unreactive. It does not, for example, react readily with bromine, which, as mentioned in Section 13.1 "Alkenes: Structures and Names", is a test for unsaturation. Note Benzene is a liquid that smells like gasoline, boils at 80°C, and freezes at 5.5°C. It is the aromatic hydrocarbon produced in the largest volume. It was formerly used to decaffeinate coffee and was a significant component of many consumer products, such as paint strippers, rubber cements, and home dry-cleaning spot removers. It was removed from many product formulations in the 1950s, but others continued to use benzene in products until the 1970s when it was associated with leukemia deaths. Benzene is still important in industry as a precursor in the production of plastics (such as Styrofoam and nylon), drugs, detergents, synthetic rubber, pesticides, and dyes. It is used as a solvent for such things as cleaning and maintaining printing equipment and for adhesives such as those used to attach soles to shoes. Benzene is a natural constituent of petroleum products, but because it is a known carcinogen, its use as an additive in gasoline is now limited. To explain the surprising properties of benzene, chemists suppose the molecule has a cyclic, hexagonal, planar structure of six carbon atoms with one hydrogen atom bonded to each. We can write a structure with alternate single and double bonds, either as a full structural formula or as a line-angle formula: However, these structures do not explain the unique properties of benzene. Furthermore, experimental evidence indicates that all the carbon-to-carbon bonds in benzene are equivalent, and the molecule is unusually stable. Chemists often represent benzene as a hexagon with an inscribed circle: The inner circle indicates that the valence electrons are shared equally by all six carbon atoms (that is, the electrons are delocalized, or spread out, over all the carbon atoms). It is understood that each corner of the hexagon is occupied by one carbon atom, and each carbon atom has one hydrogen atom attached to it. Any other atom or groups of atoms substituted for a hydrogen atom must be shown bonded to a particular corner of the hexagon. We use this modern symbolism, but many scientists still use the earlier structure with alternate double and single bonds. To Your Health: Benzene and Us Most of the benzene used commercially comes from petroleum. It is employed as a starting material for the production of detergents, drugs, dyes, insecticides, and plastics. Once widely used as an organic solvent, benzene is now known to have both short- and long-term toxic effects. The inhalation of large concentrations can cause nausea and even death due to respiratory or heart failure, while repeated exposure leads to a progressive disease in which the ability of the bone marrow to make new blood cells is eventually destroyed. This results in a condition called aplastic anemia, in which there is a decrease in the numbers of both the red and white blood cells. Answers Benzene is rather unreactive toward addition reactions compared to an alkene. Valence electrons are shared equally by all six carbon atoms (that is, the electrons are delocalized). The six electrons are shared equally by all six carbon atoms. Key Takeaway Aromatic hydrocarbons appear to be unsaturated, but they have a special type of bonding and do not undergo addition reactions. Exercises Draw the structure of benzene as if it had alternate single and double bonds. Draw the structure of benzene as chemists usually represent it today. Answer 13.8 Structure and Nomenclature of Aromatic Compounds Learning Objectives Recognize aromatic compounds from structural formulas. Name aromatic compounds given formulas. Write formulas for aromatic compounds given their names. Historically, benzene-like substances were called aromatic hydrocarbons because they had distinctive aromas. Today, an aromatic compound Any compound that contains a benzene ring or has certain benzene-like properties. is any compound that contains a benzene ring or has certain benzene-like properties (but not necessarily a strong aroma). You can recognize the aromatic compounds in this text by the presence of one or more benzene rings in their structure. Some representative aromatic compounds and their uses are listed in Table 13.3 "Some Representative Aromatic Compounds", where the benzene ring is represented as C 6 H 5. Table 13.3 Some Representative Aromatic Compounds Name Structure Typical Uses aniline C 6 H 5 –NH 2 starting material for the synthesis of dyes, drugs, resins, varnishes, perfumes; solvent; vulcanizing rubber benzoic acid C 6 H 5 –COOH food preservative; starting material for the synthesis of dyes and other organic compounds; curing of tobacco bromobenzene C 6 H 5 –Br starting material for the synthesis of many other aromatic compounds; solvent; motor oil additive nitrobenzene C 6 H 5 –NO 2 starting material for the synthesis of aniline; solvent for cellulose nitrate; in soaps and shoe polish phenol C 6 H 5 –OH disinfectant; starting material for the synthesis of resins, drugs, and other organic compounds toluene C 6 H 5 –CH 3 solvent; gasoline octane booster; starting material for the synthesis of benzoic acid, benzaldehyde, and many other organic compounds Example 5 Which compounds are aromatic? Solution The compound has a benzene ring (with a chlorine atom substituted for one of the hydrogen atoms); it is aromatic. The compound is cyclic, but it does not have a benzene ring; it is not aromatic. The compound has a benzene ring (with a propyl group substituted for one of the hydrogen atoms); it is aromatic. The compound is cyclic, but it does not have a benzene ring; it is not aromatic. Skill-Building Exercise Which compounds are aromatic? In the International Union of Pure and Applied Chemistry (IUPAC) system, aromatic hydrocarbons are named as derivatives of benzene. Figure 13.6 "Some Benzene Derivatives" shows four examples. In these structures, it is immaterial whether the single substituent is written at the top, side, or bottom of the ring: a hexagon is symmetrical, and therefore all positions are equivalent. Figure 13.6 Some Benzene Derivatives These compounds are named in the usual way with the group that replaces a hydrogen atom named as a substituent group: Cl as chloro, Br as bromo, I as iodo, NO 2 as nitro, and CH 3 CH 2 as ethyl. Although some compounds are referred to exclusively by IUPAC names, some are more frequently denoted by common names, as is indicated in Table 13.3 "Some Representative Aromatic Compounds". When there is more than one substituent, the corners of the hexagon are no longer equivalent, so we must designate the relative positions. There are three possible disubstituted benzenes, and we can use numbers to distinguish them ( Figure 13.7 "The Three Isomeric Dichlorobenzenes" ). We start numbering at the carbon atom to which one of the groups is attached and count toward the carbon atom that bears the other substituent group by the shortest path. Figure 13.7 The Three Isomeric Dichlorobenzenes In Figure 13.7 "The Three Isomeric Dichlorobenzenes", common names are also used: the prefix ortho ( o -) for 1,2-disubstitution, meta ( m -) for 1,3-disubstitution, and para ( p -) for 1,4-disubstitution. The substituent names are listed in alphabetical order. The first substituent is given the lowest number. When a common name is used, the carbon atom that bears the group responsible for the name is given the number 1: Example 6 Name each compound using both the common name and the IUPAC name. Solution The benzene ring has two chlorine atoms (dichloro) in the first and second positions. The compound is o -dichlorobenzene or 1,2-dichlorobenzene. The benzene ring has a methyl (CH 3) group. The compound is therefore named as a derivative of toluene. The bromine atom is on the fourth carbon atom, counting from the methyl group. The compound is p -bromotoluene or 4-bromotoluene. The benzene ring has two nitro (NO 2) groups in the first and third positions. It is m -dinitrobenzene or 1,3-dinitrobenzene. Note The nitro (NO 2) group is a common substituent in aromatic compounds. Many nitro compounds are explosive, most notably 2,4,6-trinitrotoluene (TNT). Skill-Building Exercise Name each compound using both the common name and the IUPAC name. Sometimes an aromatic group is found as a substituent bonded to a nonaromatic entity or to another aromatic ring. The group of atoms remaining when a hydrogen atom is removed from an aromatic compound is called an aryl group A group derived from an aromatic hydrocarbon by the removal of a hydrogen atom. . The most common aryl group is derived from benzene (C 6 H 6) by removing one hydrogen atom (C 6 H 5) and is called a phenyl group, from pheno, an old name for benzene. Polycyclic Aromatic Hydrocarbons Some common aromatic hydrocarbons consist of fused benzene rings—rings that share a common side. These compounds are called polycyclic aromatic hydrocarbons (PAHs) An aromatic hydrocarbon consisting of fused benzene rings sharing a common side. . The three examples shown here are colorless, crystalline solids generally obtained from coal tar. Naphthalene has a pungent odor and is used in mothballs. Anthracene is used in the manufacture of certain dyes. Steroids, a large group of naturally occurring substances, contain the phenanthrene structure. (For more information about steroids, see Chapter 17 "Lipids", Section 17.4 "Steroids" .) To Your Health: Polycyclic Aromatic Hydrocarbons and Cancer The intense heating required for distilling coal tar results in the formation of PAHs. For many years, it has been known that workers in coal-tar refineries are susceptible to a type of skin cancer known as tar cancer. Investigations have shown that a number of PAHs are carcinogens. One of the most active carcinogenic compounds, benzopyrene, occurs in coal tar and has also been isolated from cigarette smoke, automobile exhaust gases, and charcoal-broiled steaks. It is estimated that more than 1,000 t of benzopyrene are emitted into the air over the United States each year. Only a few milligrams of benzopyrene per kilogram of body weight are required to induce cancer in experimental animals. Biologically Important Compounds with Benzene Rings Substances containing the benzene ring are common in both animals and plants, although they are more abundant in the latter. Plants can synthesize the benzene ring from carbon dioxide, water, and inorganic materials. Animals cannot synthesize it, but they are dependent on certain aromatic compounds for survival and therefore must obtain them from food. Phenylalanine, tyrosine, and tryptophan (essential amino acids) and vitamins K, B 2 (riboflavin), and B 9 (folic acid) all contain the benzene ring. (For more information about vitamins, see Chapter 18 "Amino Acids, Proteins, and Enzymes", Section 18.9 "Enzyme Cofactors and Vitamins" .) Many important drugs, a few of which are shown in Table 13.4 "Some Drugs That Contain a Benzene Ring", also feature a benzene ring. Note So far we have studied only aromatic compounds with carbon-containing rings. However, many cyclic compounds have an element other than carbon atoms in the ring. These compounds, called heterocyclic compounds, are discussed in Chapter 15 "Organic Acids and Bases and Some of Their Derivatives", Section 15.13 "Amines as Bases". Some of these are heterocyclic aromatic compounds. Table 13.4 Some Drugs That Contain a Benzene Ring Name Structure aspirin acetaminophen ibuprofen amphetamine sulfanilamide Answers An aromatic compound is any compound that contains a benzene ring or has certain benzene-like properties. meta = 1,3 disubstitution; (answers will vary) ortho = 1,2 disubstitution para = 1,4 disubstitution or 1-bromo-4-chlorobenzene phenyl group: C 6 H 5 or 3-phenyloctane: Key Takeaway Aromatic compounds contain a benzene ring or have certain benzene-like properties; for our purposes, you can recognize aromatic compounds by the presence of one or more benzene rings in their structure. Exercises Is each compound aromatic? Is each compound aromatic? Draw the structure for each compound. toluene m -diethylbenzene 3,5-dinitrotoluene Draw the structure for each compound. p -dichlorobenzene naphthalene 1,2,4-trimethylbenzene Name each compound with its IUPAC name. Name each compound with its IUPAC name. Answers yes no ethylbenzene isopropylbenzene o -bromotoluene 3,5-dichlorotoluene 13.9 End-of-Chapter Material Chapter Summary To ensure that you understand the material in this chapter, you should review the meanings of the bold terms in the following summary and ask yourself how they relate to the topics in the chapter. Any hydrocarbon containing either a double or triple bond is an unsaturated hydrocarbon. Alkenes have a carbon-to-carbon double bond. The general formula for alkenes with one double bond is C n H 2n. Alkenes can be straight chain, branched chain, or cyclic. Simple alkenes often have common names, but all alkenes can be named by the system of the International Union of Pure and Applied Chemistry. Cis-trans isomers (or geometric isomers) are characterized by molecules that differ only in their configuration around a rigid part of the structure, such as a carbon–to-carbon double bond or a ring. The molecule having two identical (or closely related) atoms or groups on the same side is the cis isomer; the one having the two groups on opposite sides is the trans isomer. The physical properties of alkenes are quite similar to those of alkanes. Like other hydrocarbons, alkenes are insoluble in water but soluble in organic solvents. More reactive than alkanes, alkenes undergo addition reactions across the double bond: Addition of hydrogen ( hydrogenation ): CH2=CH2 + H2 → CH3CH3 Addition of halogen ( halogenation ): CH2=CH2 + X2 → XCH2CH2X where X = F, Cl, Br, or I. Addition of water ( hydration ): CH2=CH2 + HOH → HCH2CH2OH Alkenes also undergo addition polymerization, molecules joining together to form long-chain molecules. …CH2=CH2 + CH2=CH2 + CH2=CH2 +…→…CH2CH2–CH2CH2–CH2CH2–… The reactant units are monomers, and the product is a polymer. Alkynes have a carbon-to-carbon triple bond. The general formula for alkynes is C n H 2n − 2. The properties of alkynes are quite similar to those of alkenes. They are named much like alkenes but with the ending - yne. The cyclic hydrocarbon benzene (C 6 H 6) has a ring of carbon atoms. The molecule seems to be unsaturated, but it does not undergo the typical reactions expected of alkenes. The electrons that might be fixed in three double bonds are instead delocalized over all six carbon atoms. A hydrocarbon containing one or more benzene rings (or other similarly stable electron arrangements) is an aromatic hydrocarbon, and any related substance is an aromatic compound. One or more of the hydrogen atoms on a benzene ring can be replaced by other atoms. When two hydrogen atoms are replaced, the product name is based on the relative position of the replacement atoms (or atom groups). A 1,2-disubstituted benzene is designated as an ortho ( o -) isomer; 1,3-, a meta ( m -) isomer; and 1,4-, a para ( p -) isomer. An aromatic group as a substituent is called an aryl group. A polycyclic aromatic hydrocarbon (PAH) has fused benzene rings sharing a common side. Additional Exercises Classify each compound as saturated or unsaturated. CH 3 C≡CCH 3 Classify each compound as saturated or unsaturated. Give the molecular formula for each compound. When three isomeric pentenes—X, Y, and Z—are hydrogenated, all three form 2-methylbutane. The addition of Cl 2 to Y gives 1,2-dichloro-3-methylbutane, and the addition of Cl 2 to Z gives 1,2-dichloro-2-methylbutane. Draw the original structures for X, Y, and Z. Pentane and 1-pentene are both colorless, low-boiling liquids. Describe a simple test that distinguishes the two compounds. Indicate what you would observe. Draw and name all the alkene cis-trans isomers corresponding to the molecular formula C 5 H 10. (Hint: there are only two.) The complete combustion of benzene forms carbon dioxide and water: C6H6 + O2 → CO2 + H2O Balance the equation. What mass, in grams, of carbon dioxide is formed by the complete combustion of 39.0 g of benzene? Describe a physiological effect of some PAHs. What are some of the hazards associated with the use of benzene? What is wrong with each name? Draw the structure and give the correct name for each compound. 2-methyl-4-heptene 2-ethyl-2-hexene 2,2-dimethyl-3-pentene What is wrong with each name? 2-bromobenzene 3,3-dichlorotoluene 1,4-dimethylnitrobenzene Following are line-angle formulas for three compounds. Draw the structure and give the name for each. Following are ball-and-stick molecular models for three compounds (blue balls represent H atoms; red balls are C atoms). Write the condensed structural formula and give the name for each. Answers unsaturated unsaturated C 6 H 10 C 4 H 8 Add bromine solution (reddish-brown) to each. Pentane will not react, and the reddish-brown color persists; 1-pentene will react, leaving a colorless solution. 2C 6 H 6 + 15O 2 → 12CO 2 + 6H 2 O; 132 g carcinogenic, flammable number not needed can’t have two groups on one carbon atom on a benzene ring can’t have a substituent on the same carbon atom as the nitro group CH 3 CH=CHCH 2 CH 2 CH 3; 2-hexene	msmarco_doc_00_11884382
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s17-08-ethers.html	Ethers	14.8 Ethers 14.8 Ethers Learning Objectives Example 5 Skill-Building Exercise To Your Health: Ethers as General Anesthetics Answers Key Takeaways Exercises Answers	Ethers 14.8 Ethers Learning Objectives Describe the structural difference between an alcohol and an ether that affects physical characteristics and reactivity of each. Name simple ethers. Describe the structure and uses of some ethers. With the general formula ROR′, an ether An organic compound that has an oxygen atom between two hydrocarbon groups. may be considered a derivative of water in which both hydrogen atoms are replaced by alkyl or aryl groups. It may also be considered a derivative of an alcohol (ROH) in which the hydrogen atom of the OH group is been replaced by a second alkyl or aryl group: HOH → H atoms replace both ROR′ ← of OH group replace H atom ROH Simple ethers have simple common names, formed from the names of the groups attached to oxygen atom, followed by the generic name ether. For example, CH 3 –O–CH 2 CH 2 CH 3 is methyl propyl ether. If both groups are the same, the group name should be preceded by the prefix di -, as in dimethyl ether (CH 3 –O–CH 3) and diethyl ether CH 3 CH 2 –O–CH 2 CH 3. Ether molecules have no hydrogen atom on the oxygen atom (that is, no OH group). Therefore there is no intermolecular hydrogen bonding between ether molecules, and ethers therefore have quite low boiling points for a given molar mass. Indeed, ethers have boiling points about the same as those of alkanes of comparable molar mass and much lower than those of the corresponding alcohols ( Table 14.4 "Comparison of Boiling Points of Alkanes, Alcohols, and Ethers" ). Table 14.4 Comparison of Boiling Points of Alkanes, Alcohols, and Ethers Condensed Structural Formula Name Molar Mass Boiling Point (°C) Intermolecular Hydrogen Bonding in Pure Liquid? CH 3 CH 2 CH 3 propane 44 –42 no CH 3 OCH 3 dimethyl ether 46 –25 no CH 3 CH 2 OH ethyl alcohol 46 78 yes CH 3 CH 2 CH 2 CH 2 CH 3 pentane 72 36 no CH 3 CH 2 OCH 2 CH 3 diethyl ether 74 35 no CH 3 CH 2 CH 2 CH 2 OH butyl alcohol 74 117 yes Ether molecules do have an oxygen atom, however, and engage in hydrogen bonding with water molecules. Consequently, an ether has about the same solubility in water as the alcohol that is isomeric with it. For example, dimethyl ether and ethanol (both having the molecular formula C 2 H 6 O) are completely soluble in water, whereas diethyl ether and 1-butanol (both C 4 H 10 O) are barely soluble in water (8 g/100 mL of water). Example 5 What is the common name for each ether? CH 3 CH 2 CH 2 OCH 2 CH 2 CH 3 Solution The carbon groups on either side of the oxygen atom are propyl (CH 3 CH 2 CH 2) groups, so the compound is dipropyl ether. The three-carbon group is attached by the middle carbon atom, so it is an isopropyl group. The one-carbon group is a methyl group. The compound is isopropyl methyl ether. Skill-Building Exercise What is the common name for each ether? CH 3 CH 2 CH 2 CH 2 OCH 2 CH 2 CH 2 CH 3 To Your Health: Ethers as General Anesthetics A general anesthetic acts on the brain to produce unconsciousness and a general insensitivity to feeling or pain. Diethyl ether (CH 3 CH 2 OCH 2 CH 3) was the first general anesthetic to be used. William Morton, a Boston dentist, introduced diethyl ether into surgical practice in 1846. This painting shows an operation in Boston in 1846 in which diethyl ether was used as an anesthetic. Inhalation of ether vapor produces unconsciousness by depressing the activity of the central nervous system. Source: Painting of William Morton by Ernest Board, from http://commons.wikimedia.org/wiki/File:Morton_Ether_1846.jpg. Diethyl ether is relatively safe because there is a fairly wide gap between the dose that produces an effective level of anesthesia and the lethal dose. However, because it is highly flammable and has the added disadvantage of causing nausea, it has been replaced by newer inhalant anesthetics, including the fluorine-containing compounds halothane, enflurane, and isoflurane. Unfortunately, the safety of these compounds for operating room personnel has been questioned. For example, female operating room workers exposed to halothane suffer a higher rate of miscarriages than women in the general population. These three modern, inhalant, halogen-containing, anesthetic compounds are less flammable than diethyl ether. Answers Diethyl ether has no intermolecular hydrogen bonding because there is no OH group; 1-butanol has an OH and engages in intermolecular hydrogen bonding. Ethyl methyl ether (three carbon atoms, one oxygen atom) is more soluble in water than 1-butanol (four carbon atoms, one oxygen atom), even though both can engage in hydrogen bonding with water. Key Takeaways To give ethers common names, simply name the groups attached to the oxygen atom, followed by the generic name ether. If both groups are the same, the group name should be preceded by the prefix di -. Ether molecules have no OH group and thus no intermolecular hydrogen bonding. Ethers therefore have quite low boiling points for a given molar mass. Ether molecules have an oxygen atom and can engage in hydrogen bonding with water molecules. An ether molecule has about the same solubility in water as the alcohol that is isomeric with it. Exercises How can ethanol give two different products when heated with sulfuric acid? Name these products. Which of these ethers is isomeric with ethanol—CH 3 CH 2 OCH 2 CH 3, CH 3 OCH 2 CH 3, or CH 3 OCH 3? Name each compound. CH 3 OCH 2 CH 2 CH 3 Name each compound. CH 3 CH 2 CH 2 CH 2 OCH 3 CH 3 CH 2 OCH 2 CH 2 CH 3 Draw the structure for each compound. methyl ethyl ether tert -butyl ethyl ether Draw the structure for each compound. diisopropyl ether cyclopropyl propyl ether Answers Intramolecular (both the H and the OH come from the same molecule) dehydration gives ethylene; intermolecular (the H comes from one molecule and the OH comes from another molecule) dehydration gives diethyl ether. methyl propyl ether ethyl isopropyl ether CH 3 OCH 2 CH 3	msmarco_doc_00_11933220
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s17-09-aldehydes-and-ketones-structur.html	Aldehydes and Ketones: Structure and Names	14.9 Aldehydes and Ketones: Structure and Names 14.9 Aldehydes and Ketones: Structure and Names Learning Objectives Note Naming Aldehydes and Ketones Note Example 6 Skill-Building Exercise Example 7 Skill-Building Exercise Example 8 Skill-Building Exercise Answers Key Takeaways Exercises Answers	Aldehydes and Ketones: Structure and Names 14.9 Aldehydes and Ketones: Structure and Names Learning Objectives Identify the general structure for an aldehyde and a ketone. Use common names to name aldehydes and ketones. Use the IUPAC system to name aldehydes and ketones. The next functional group we consider, the carbonyl group A compound with an carbon-to-oxygen double bond. , has a carbon-to-oxygen double bond. Carbonyl groups define two related families of organic compounds: the aldehydes and the ketones. Note The carbonyl group is ubiquitous in biological compounds. It is found in carbohydrates, fats, proteins, nucleic acids, hormones, and vitamins—organic compounds critical to living systems. In a ketone An organic compound whose molecules have a carbonyl functional group between two hydrocarbon groups. , two carbon groups are attached to the carbonyl carbon atom. The following general formulas, in which R represents an alkyl group and Ar stands for an aryl group, represent ketones. In an aldehyde An organic compound with a carbonyl functional group that has an hydrogen atom attached and either a hydrocarbon group or a second hydrogen atom. , at least one of the attached groups must be a hydrogen atom. The following compounds are aldehydes: In condensed formulas, we use CHO to identify an aldehyde rather than COH, which might be confused with an alcohol. This follows the general rule that in condensed structural formulas H comes after the atom it is attached to (usually C, N, or O). The carbon-to-oxygen double bond is not shown but understood to be present. Because they contain the same functional group, aldehydes and ketones share many common properties, but they still differ enough to warrant their classification into two families. Naming Aldehydes and Ketones Both common and International Union of Pure and Applied Chemistry (IUPAC) names are frequently used for aldehydes and ketones, with common names predominating for the lower homologs. The common names of aldehydes are taken from the names of the acids into which the aldehydes can be converted by oxidation. (For more information about carboxylic acids, see Chapter 15 "Organic Acids and Bases and Some of Their Derivatives", Section 15.2 "Carboxylic Acids: Structures and Names" through Section 15.4 "Physical Properties of Carboxylic Acids" .) Note The stems for the common names of the first four aldehydes are as follows: 1 carbon atom: form - 2 carbon atoms: acet - 3 carbon atoms: propion - 4 carbon atoms: butyr - Because the carbonyl group in a ketone must be attached to two carbon groups, the simplest ketone has three carbon atoms. It is widely known as acetone, a unique name unrelated to other common names for ketones. Generally, the common names of ketones consist of the names of the groups attached to the carbonyl group, followed by the word ketone. (Note the similarity to the naming of ethers.) Another name for acetone, then, is dimethyl ketone. The ketone with four carbon atoms is ethyl methyl ketone. Example 6 Classify each compound as an aldehyde or a ketone. Give the common name for each ketone. Solution This compound has the carbonyl group on an end carbon atom, so it is an aldehyde. This compound has the carbonyl group on an interior carbon atom, so it is a ketone. Both alkyl groups are propyl groups. The name is therefore dipropyl ketone. This compound has the carbonyl group between two alkyl groups, so it is a ketone. One alkyl group has three carbon atoms and is attached by the middle carbon atom; it is an isopropyl group. A group with one carbon atom is a methyl group. The name is therefore isopropyl methyl ketone. Skill-Building Exercise Classify each compound as an aldehyde or a ketone. Give the common name for each ketone. Here are some simple IUPAC rules for naming aldehydes and ketones: The stem names of aldehydes and ketones are derived from those of the parent alkanes, defined by the longest continuous chain (LCC) of carbon atoms that contains the functional group. For an aldehyde, drop the - e from the alkane name and add the ending - al. Methanal is the IUPAC name for formaldehyde, and ethanal is the name for acetaldehyde. For a ketone, drop the - e from the alkane name and add the ending - one. Propanone is the IUPAC name for acetone, and butanone is the name for ethyl methyl ketone. To indicate the position of a substituent on an aldehyde, the carbonyl carbon atom is always considered to be C1; it is unnecessary to designate this group by number. To indicate the position of a substituent on a ketone, number the chain in the manner that gives the carbonyl carbon atom the lowest possible number. In cyclic ketones, it is understood that the carbonyl carbon atom is C1. Example 7 Give the IUPAC name for each compound. Solution There are five carbon atoms in the LCC. The methyl group (CH 3) is a substituent on the second carbon atom of the chain; the aldehyde carbon atom is always C1. The name is derived from pentane. Dropping the - e and adding the ending - al gives pentanal. The methyl group on the second carbon atom makes the name 2-methylpentanal. There are five carbon atoms in the LCC. The carbonyl carbon atom is C3, and there are methyl groups on C2 and C4. The IUPAC name is 2,4-dimethyl-3-pentanone. There are six carbon atoms in the ring. The compound is cyclohexanone. No number is needed to indicate the position of the carbonyl group because all six carbon atoms are equivalent. Skill-Building Exercise Give the IUPAC name for each compound. Example 8 Draw the structure for each compound. 7-chlorooctanal 4-methyl–3-hexanone Solution The octan - part of the name tells us that the LCC has eight carbon atoms. There is a chlorine (Cl) atom on the seventh carbon atom; numbering from the carbonyl group and counting the carbonyl carbon atom as C1, we place the Cl atom on the seventh carbon atom. The hexan - part of the name tells us that the LCC has six carbon atoms. The 3 means that the carbonyl carbon atom is C3 in this chain, and the 4 tells us that there is a methyl (CH 3) group at C4: Skill-Building Exercise Draw the structure for each compound. 5-bromo-3-iodoheptanal 5-bromo-4-ethyl-2-heptanone Answers 3-bromobenzaldehyde 2,3-dihydroxypropanal Key Takeaways The common names of aldehydes are taken from the names of the corresponding carboxylic acids: formaldehyde, acetaldehyde, and so on. The common names of ketones, like those of ethers, consist of the names of the groups attached to the carbonyl group, followed by the word ketone. Stem names of aldehydes and ketones are derived from those of the parent alkanes, using an - al ending for an aldehydes and an - one ending for a ketone. Exercises Name each compound. Name each compound. CH 3 CH 2 CH 2 CH 2 CH 2 CHO Draw the structure for each compound. butyraldehyde 2-hexanone p -nitrobenzaldehyde Draw the structure for each compound. 5-ethyloctanal 2-chloropropanal 2-hydroxy-3-pentanone Answers propanal or propionaldehyde butanal or butyraldehyde 3-pentanone or diethyl ketone benzaldehyde CH 3 CH 2 CH 2 CHO	msmarco_doc_00_11939663
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s18-09-hydrolysis-of-esters.html	Hydrolysis of Esters	15.9 Hydrolysis of Esters 15.9 Hydrolysis of Esters Learning Objectives Example 7 Skill-Building Exercise Example 8 Skill-Building Exercise Answers Key Takeaways Exercises Answers	Hydrolysis of Esters 15.9 Hydrolysis of Esters Learning Objectives Describe the typical reaction that takes place with esters. Identify the products of an acidic hydrolysis of an ester. Identify the products of a basic hydrolysis of an ester. Esters are neutral compounds, unlike the acids from which they are formed. In typical reactions, the alkoxy (OR′) group of an ester is replaced by another group. One such reaction is hydrolysis The reaction of a substance with water. , literally “splitting with water.” The hydrolysis of esters is catalyzed by either an acid or a base. Acidic hydrolysis is simply the reverse of esterification. The ester is heated with a large excess of water containing a strong-acid catalyst. Like esterification, the reaction is reversible and does not go to completion. As a specific example, butyl acetate and water react to form acetic acid and 1-butanol. The reaction is reversible and does not go to completion. Example 7 Write an equation for the acidic hydrolysis of ethyl butyrate (CH 3 CH 2 CH 2 COOCH 2 CH 3) and name the products. Solution Remember that in acidic hydrolysis, water (HOH) splits the ester bond. The H of HOH joins to the oxygen atom in the OR part of the original ester, and the OH of HOH joins to the carbonyl carbon atom: The products are butyric acid (butanoic acid) and ethanol. Skill-Building Exercise Write an equation for the acidic hydrolysis of methyl butanoate and name the products. When a base (such as sodium hydroxide [NaOH] or potassium hydroxide [KOH]) is used to hydrolyze an ester, the products are a carboxylate salt and an alcohol. Because soaps are prepared by the alkaline hydrolysis of fats and oils, alkaline hydrolysis of esters is called saponification The hydrolysis of fats and oils in the presence of a base to make soap. (Latin sapon, meaning “soap,” and facere, meaning “to make”). In a saponification reaction, the base is a reactant, not simply a catalyst. The reaction goes to completion: As a specific example, ethyl acetate and NaOH react to form sodium acetate and ethanol: Example 8 Write an equation for the hydrolysis of methyl benzoate in a potassium hydroxide solution. Solution In basic hydrolysis, the molecule of the base splits the ester linkage. The acid portion of the ester ends up as the salt of the acid (in this case, the potassium salt). The alcohol portion of the ester ends up as the free alcohol. Skill-Building Exercise Write the equation for the hydrolysis of ethyl propanoate in a sodium hydroxide solution. Answers acidic hydrolysis: carboxylic acid + alcohol; basic hydrolysis: carboxylate salt + alcohol basic hydrolysis: completion; acidic hydrolysis: incomplete reaction the basic hydrolysis of an ester Key Takeaways Hydrolysis is a most important reaction of esters. Acidic hydrolysis of an ester gives a carboxylic acid and an alcohol. Basic hydrolysis of an ester gives a carboxylate salt and an alcohol. Exercises Write an equation for the acid-catalyzed hydrolysis of ethyl acetate. Write an equation for the base-catalyzed hydrolysis of ethyl acetate. Complete each equation. Complete each equation. (CH 3) 2 CHCOOCH 2 CH 3 + H 2 O ⇄ H + CH 3 COOCH (CH 3) 2 + KOH (aq) → Answers CH 3 COOCH 2 CH 3 + H 2 O → H + CH 3 COOH + CH 3 CH 2 OH CH 3 COONa (aq) + CH 3 CH 2 CH 2 OH CH 3 CH 2 CH 2 COOH + CH 3 CH 2 OH	msmarco_doc_00_11947423
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s18-14-amides-structures-and-names.html	Amides: Structures and Names	15.14 Amides: Structures and Names 15.14 Amides: Structures and Names Learning Objectives Note Example 16 Skill-Building Exercise Answers Key Takeaways Exercises Answers	Amides: Structures and Names 15.14 Amides: Structures and Names Learning Objectives Identify the general structure for an amide. Identify the functional group for an amide. Names amides with common names. Name amides according to the IUPAC system. The amide functional group has an nitrogen atom attached to a carbonyl carbon atom. If the two remaining bonds on the nitrogen atom are attached to hydrogen atoms, the compound is a simple amide. If one or both of the two remaining bonds on the atom are attached to alkyl or aryl groups, the compound is a substituted amide. Note The carbonyl carbon-to-nitrogen bond is called an amide linkage. This bond is quite stable and is found in the repeating units of protein molecules, where it is called a peptide linkage. (For more about peptide linkages, see Chapter 18 "Amino Acids, Proteins, and Enzymes", Section 18.3 "Peptides" .) Simple amides are named as derivatives of carboxylic acids. The - ic ending of the common name or the - oic ending of the International Union of Pure and Applied Chemistry (IUPAC) name of the carboxylic acid is replaced with the suffix - amide. Example 16 Name each compound with the common name, the IUPAC name, or both. Solution This amide has two carbon atoms and is thus derived from acetic acid. The OH of acetic acid is replaced by an NH 2 group. The - ic from acetic (or - oic from ethanoic) is dropped, and - amide is added to give acetamide (or ethanamide in the IUPAC system). This amide is derived from benzoic acid. The - oic is dropped, and - amide is added to give benzamide. Skill-Building Exercise Name each compound with the common name, the IUPAC name, or both. Answers β-bromobutyramide (3-bromobutanamide) Key Takeaways Amides have a general structure in which a nitrogen atom is bonded to a carbonyl carbon atom. The functional group for an amide is as follows: In names for amides, the - ic acid of the common name or the - oic ending of the IUPAC for the corresponding carboxylic acid is replaced by - amide. Exercises Draw the structure for each compound. formamide hexanamide Draw the structure for each compound. propionamide butanamide Name each compound with the common name, the IUPAC name, or both. Name the compound. Answers propionamide (propanamide) α-methylbutyramide (2-methylbutanamide)	msmarco_doc_00_11951285
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s19-02-classes-of-monosaccharides.html	Classes of Monosaccharides	16.2 Classes of Monosaccharides 16.2 Classes of Monosaccharides Learning Objectives Example 2 Skill-Building Exercise Note Note Looking Closer: Polarized Light Answers Key Takeaways Exercises Answers	Classes of Monosaccharides 16.2 Classes of Monosaccharides Learning Objectives Classify monosaccharides as aldoses or ketoses and as trioses, tetroses, pentoses, or hexoses. Distinguish between a D sugar and an L sugar. The naturally occurring monosaccharides contain three to seven carbon atoms per molecule. Monosaccharides of specific sizes may be indicated by names composed of a stem denoting the number of carbon atoms and the suffix - ose. For example, the terms triose, tetrose, pentose, and hexose signify monosaccharides with, respectively, three, four, five, and six carbon atoms. Monosaccharides are also classified as aldoses or ketoses. Those monosaccharides that contain an aldehyde functional group are called aldoses A monosaccharide that contains an aldehyde functional group. ; those containing a ketone functional group on the second carbon atom are ketoses A monosaccharide that contains a ketone functional group on the second carbon atom. . Combining these classification systems gives general names that indicate both the type of carbonyl group and the number of carbon atoms in a molecule. Thus, monosaccharides are described as aldotetroses, aldopentoses, ketopentoses, ketoheptoses, and so forth. Glucose and fructose are specific examples of an aldohexose and a ketohexose, respectively. Example 2 Draw an example of each type of compound. a ketopentose an aldotetrose Solution The structure must have five carbon atoms with the second carbon atom being a carbonyl group and the other four carbon atoms each having an OH group attached. Several structures are possible, but one example is shown. The structure must have four carbon atoms with the first carbon atom part of the aldehyde functional group. The other three carbon atoms each have an OH group attached. Several structures are possible, but one example is shown. Skill-Building Exercise Draw an example of each type of compound. an aldohexose a ketotetrose The simplest sugars are the trioses. The possible trioses are shown in part (a) of Figure 16.2 "Structures of the Trioses"; glyceraldehyde is an aldotriose, while dihydroxyacetone is a ketotriose. Notice that two structures are shown for glyceraldehyde. These structures are stereoisomers An isomer that has the same structural formula but differs in the arrangement of atoms or groups of atoms in three-dimensional space. , isomers having the same structural formula but differing in the arrangement of atoms or groups of atoms in three-dimensional space. If you make models of the two stereoisomers of glyceraldehyde, you will find that you cannot place one model on top of the other and have each functional group point in the same direction. However, if you place one of the models in front of a mirror, the image in the mirror will be identical to the second stereoisomer in part (b) of Figure 16.2 "Structures of the Trioses". Molecules that are nonsuperimposable (nonidentical) mirror images of each other are a type of stereoisomer called enantiomers Stereoisomers that are nonsuperimposable mirror images of each other. (Greek enantios, meaning “opposite”). Note Cis-trans (geometric) isomers were discussed in Chapter 13 "Unsaturated and Aromatic Hydrocarbons", Section 13.2 "Cis-Trans Isomers (Geometric Isomers)". These are another type of stereoisomers. Figure 16.2 Structures of the Trioses (a) D- and L-glyceraldehyde are mirror images of each other and represent a pair of enantiomers. (b) A ball-and-stick model of D-glyceraldehyde is reflected in a mirror. Note that the reflection has the same structure as L-glyceraldehyde. A key characteristic of enantiomers is that they have a carbon atom to which four different groups are attached. Note, for example, the four different groups attached to the central carbon atom of glyceraldehyde (part (a) of Figure 16.2 "Structures of the Trioses" ). A carbon atom that has four different groups attached is a chiral carbon A carbon atom that has four different groups attached to it. . If a molecule contains one or more chiral carbons, it is likely to exist as two or more stereoisomers. Dihydroxyacetone does not contain a chiral carbon and thus does not exist as a pair of stereoisomers. Glyceraldehyde, however, has a chiral carbon and exists as a pair of enantiomers. Except for the direction in which each enantiomer rotates plane-polarized light, these two molecules have identical physical properties. One enantiomer has a specific rotation of +8.7°, while the other has a specific rotation of −8.7°. H. Emil Fischer, a German chemist, developed the convention commonly used for writing two-dimensional representations of the monosaccharides, such as those in part (a) of Figure 16.2 "Structures of the Trioses". In these structural formulas, the aldehyde group is written at the top, and the hydrogen atoms and OH groups that are attached to each chiral carbon are written to the right or left. (If the monosaccharide is a ketose, the ketone functional group is the second carbon atom.) Vertical lines represent bonds pointing away from you, while horizontal lines represent bonds coming toward you. The formulas of chiral molecules represented in this manner are referred to as Fischer projections. The two enantiomers of glyceraldehyde are especially important because monosaccharides with more than three carbon atoms can be considered as being derived from them. Thus, D- and L-glyceraldehyde provide reference points for designating and drawing all other monosaccharides. Sugars whose Fischer projections terminate in the same configuration as D-glyceraldehyde are designated as D sugars A sugar whose Fischer projection terminates in the same configuration as D-glyceraldehyde. ; those derived from L-glyceraldehyde are designated as L sugars A sugar whose Fischer projection terminates in the same configuration as L-glyceraldehyde. . Note By convention, the penultimate (next-to-last) carbon atom has been chosen as the carbon atom that determines if a sugar is D or L. It is the chiral carbon farthest from the aldehyde or ketone functional group. Looking Closer: Polarized Light A beam of ordinary light can be pictured as a bundle of waves; some move up and down, some sideways, and others at all other conceivable angles. When a beam of light has been polarized, however, the waves in the bundle all vibrate in a single plane. Light altered in this way is called plane-polarized light. Much of what chemists know about stereoisomers comes from studying the effects they have on plane-polarized light. In this illustration, the light on the left is not polarized, while that on the right is polarized. Sunlight, in general, is not polarized; light from an ordinary light bulb or an ordinary flashlight is not polarized. One way to polarize ordinary light is to pass it through Polaroid sheets, special plastic sheets containing carefully oriented organic compounds that permit only light vibrating in a single plane to pass through. To the eye, polarized light doesn’t “look” any different from nonpolarized light. We can detect polarized light, however, by using a second sheet of polarizing material, as shown here. In the photo on the left, two Polaroid sheets are aligned in the same direction; plane-polarized light from the first Polaroid sheet can pass through the second sheet. In the photo on the right, the top Polaroid sheet has been rotated 90° and now blocks the plane-polarized light that comes through the first Polaroid sheet. Certain substances act on polarized light by rotating the plane of vibration. Such substances are said to be optically active. The extent of optical activity is measured by a polarimeter, an instrument that contains two polarizing lenses separated by a sample tube, as shown in the accompanying figure. With the sample tube empty, maximum light reaches the observer’s eye when the two lenses are aligned so that both pass light vibrating in the same plane. When an optically active substance is placed in the sample tube, that substance rotates the plane of polarization of the light passing through it, so that the polarized light emerging from the sample tube is vibrating in a different direction than when it entered the tube. To see the maximum amount of light when the sample is in place, the observer must rotate one lens to accommodate the change in the plane of polarization. Figure 16.3 Diagram of a Polarimeter Some optically active substances rotate the plane of polarized light to the right (clockwise) from the observer’s point of view. These compounds are said to be dextrorotatory; substances that rotate light to the left (counterclockwise) are levorotatory. To denote the direction of rotation, a positive sign (+) is given to dextrorotatory substances, and a negative sign (−) is given to levorotatory substances. Answers A chiral carbon is a carbon atom with four different groups attached to it. Enantiomers are mirror images of each other; they differ in the arrangements of atoms around a chiral carbon. Key Takeaways Monosaccharides can be classified by the number of carbon atoms in the structure and/or the type of carbonyl group they contain (aldose or ketose). Most monosaccharides contain at least one chiral carbon and can form stereoisomers. Enantiomers are a specific type of stereoisomers that are mirror images of each other. Exercises Identify each sugar as an aldose or a ketose and then as a triose, tetrose, pentose, or hexose. D-glucose L-ribulose D-glyceraldehyde Identify each sugar as an aldose or a ketose and then as a triose, tetrose, pentose, or hexose. dihydroxyacetone D-ribose D-galactose Identify each sugar as an aldose or a ketose and then as a D sugar or an L sugar. Identify each sugar as an aldose or a ketose and then as a D sugar or an L sugar. Answers aldose; hexose ketose; pentose aldose; triose	msmarco_doc_00_11954070
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s19-04-cyclic-structures-of-monosacch.html	Cyclic Structures of Monosaccharides	16.4 Cyclic Structures of Monosaccharides 16.4 Cyclic Structures of Monosaccharides Learning Objectives Answers Key Takeaways Exercises Answers	Cyclic Structures of Monosaccharides 16.4 Cyclic Structures of Monosaccharides Learning Objectives Define what is meant by anomers and describe how they are formed. Explain what is meant by mutarotation. So far we have represented monosaccharides as linear molecules, but many of them also adopt cyclic structures. This conversion occurs because of the ability of aldehydes and ketones to react with alcohols: In some cases, OH and carbonyl groups on the same molecule are able to react with one another in an intramolecular reaction. Thus, monosaccharides larger than tetroses exist mainly as cyclic compounds ( Figure 16.5 "Cyclization of D-Glucose" ). You might wonder why the aldehyde reacts with the OH group on the fifth carbon atom rather than the OH group on the second carbon atom next to it. Recall from Chapter 12 "Organic Chemistry: Alkanes and Halogenated Hydrocarbons", Section 12.9 "Cycloalkanes", that cyclic alkanes containing five or six carbon atoms in the ring are the most stable. The same is true for monosaccharides that form cyclic structures: rings consisting of five or six carbon atoms are the most stable. Figure 16.5 Cyclization of D-Glucose D-Glucose can be represented with a Fischer projection (a) or three dimensionally (b). By reacting the OH group on the fifth carbon atom with the aldehyde group, the cyclic monosaccharide (c) is produced. When a straight-chain monosaccharide, such as any of the structures shown in Figure 16.4 "Structures of Three Important Hexoses", forms a cyclic structure, the carbonyl oxygen atom may be pushed either up or down, giving rise to two stereoisomers, as shown in Figure 16.6 "Monosaccharides". The structure shown on the left side of Figure 16.6 "Monosaccharides", with the OH group on the first carbon atom projected downward, represent what is called the alpha (α) form. The structures on the right side, with the OH group on the first carbon atom pointed upward, is the beta (β) form. These two stereoisomers of a cyclic monosaccharide are known as anomers Stereoisomers that differ in structure around what was the carbonyl carbon atom in the straight-chain form of a monosaccharide. ; they differ in structure around the anomeric carbon The carbon atom that was the carbonyl carbon atom in the straight-chain form of a monosaccharide. —that is, the carbon atom that was the carbonyl carbon atom in the straight-chain form. Figure 16.6 Monosaccharides In an aqueous solution, monosaccharides exist as an equilibrium mixture of three forms. The interconversion between the forms is known as mutarotation, which is shown for D-glucose (a) and D-fructose (b). It is possible to obtain a sample of crystalline glucose in which all the molecules have the α structure or all have the β structure. The α form melts at 146°C and has a specific rotation of +112°, while the β form melts at 150°C and has a specific rotation of +18.7°. When the sample is dissolved in water, however, a mixture is soon produced containing both anomers as well as the straight-chain form, in dynamic equilibrium (part (a) of Figure 16.6 "Monosaccharides" ). You can start with a pure crystalline sample of glucose consisting entirely of either anomer, but as soon as the molecules dissolve in water, they open to form the carbonyl group and then reclose to form either the α or the β anomer. The opening and closing repeats continuously in an ongoing interconversion between anomeric forms and is referred to as mutarotation The ongoing interconversion between anomeric forms of a monosaccharide to form an equilibrium mixture. (Latin mutare, meaning “to change”). At equilibrium, the mixture consists of about 36% α-D-glucose, 64% β-D-glucose, and less than 0.02% of the open-chain aldehyde form. The observed rotation of this solution is +52.7°. Even though only a small percentage of the molecules are in the open-chain aldehyde form at any time, the solution will nevertheless exhibit the characteristic reactions of an aldehyde. As the small amount of free aldehyde is used up in a reaction, there is a shift in the equilibrium to yield more aldehyde. Thus, all the molecules may eventually react, even though very little free aldehyde is present at a time. In Figure 16.5 "Cyclization of D-Glucose" and Figure 16.6 "Monosaccharides", and elsewhere in this book, the cyclic forms of sugars are depicted using a convention first suggested by Walter N. Haworth, an English chemist. The molecules are drawn as planar hexagons with a darkened edge representing the side facing toward the viewer. The structure is simplified to show only the functional groups attached to the carbon atoms. Any group written to the right in a Fischer projection appears below the plane of the ring in a Haworth projection, and any group written to the left in a Fischer projection appears above the plane in a Haworth projection. The difference between the α and the β forms of sugars may seem trivial, but such structural differences are often crucial in biochemical reactions. This explains why we can get energy from the starch in potatoes and other plants but not from cellulose, even though both starch and cellulose are polysaccharides composed of glucose molecules linked together. We will examine the effects of these differences more closely in Section 16.7 "Polysaccharides" and when we discuss enzyme specificity in Chapter 18 "Amino Acids, Proteins, and Enzymes", Section 18.5 "Enzymes". Answers the ongoing interconversion between anomers of a particular carbohydrate to form an equilibrium mixture a stereoisomer that differs in structure around what was the carbonyl carbon atom in the straight-chain form of a monosaccharide the carbon atom that was the carbonyl carbon atom in the straight-chain form of a monosaccharide Place a sample of pure α-D-glucose in a polarimeter and measure its observed rotation. This value will change as mutarotation occurs. Key Takeaways Monosaccharides that contain five or more carbons atoms form cyclic structures in aqueous solution. Two cyclic stereoisomers can form from each straight-chain monosaccharide; these are known as anomers. In an aqueous solution, an equilibrium mixture forms between the two anomers and the straight-chain structure of a monosaccharide in a process known as mutarotation. Exercises Draw the cyclic structure for β-D-glucose. Identify the anomeric carbon. Draw the cyclic structure for α-D-fructose. Identify the anomeric carbon. Given that the aldohexose D-mannose differs from D-glucose only in the configuration at the second carbon atom, draw the cyclic structure for α-D-mannose. Given that the aldohexose D-allose differs from D-glucose only in the configuration at the third carbon atom, draw the cyclic structure for β-D-allose. Answers	msmarco_doc_00_11964501
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s19-07-polysaccharides.html	Polysaccharides	16.7 Polysaccharides 16.7 Polysaccharides Learning Objective Starch Glycogen Note Cellulose Career Focus: Certified Diabetes Educator Answers Key Takeaways Exercises Answers	Polysaccharides 16.7 Polysaccharides Learning Objective Compare and contrast the structures and uses of starch, glycogen, and cellulose. The polysaccharides are the most abundant carbohydrates in nature and serve a variety of functions, such as energy storage or as components of plant cell walls. Polysaccharides are very large polymers composed of tens to thousands of monosaccharides joined together by glycosidic linkages. The three most abundant polysaccharides are starch, glycogen, and cellulose. These three are referred to as homopolymers because each yields only one type of monosaccharide (glucose) after complete hydrolysis. Heteropolymers may contain sugar acids, amino sugars, or noncarbohydrate substances in addition to monosaccharides. Heteropolymers are common in nature (gums, pectins, and other substances) but will not be discussed further in this textbook. The polysaccharides are nonreducing carbohydrates, are not sweet tasting, and do not undergo mutarotation. Starch Starch is the most important source of carbohydrates in the human diet and accounts for more than 50% of our carbohydrate intake. It occurs in plants in the form of granules, and these are particularly abundant in seeds (especially the cereal grains) and tubers, where they serve as a storage form of carbohydrates. The breakdown of starch to glucose nourishes the plant during periods of reduced photosynthetic activity. We often think of potatoes as a “starchy” food, yet other plants contain a much greater percentage of starch (potatoes 15%, wheat 55%, corn 65%, and rice 75%). Commercial starch is a white powder. Starch is a mixture of two polymers: amylose A linear polymer of glucose units found in starch. and amylopectin A branched polymer of glucose units found in starch. . Natural starches consist of about 10%–30% amylase and 70%–90% amylopectin. Amylose is a linear polysaccharide composed entirely of D-glucose units joined by the α-1,4-glycosidic linkages we saw in maltose (part (a) of Figure 16.9 "Amylose" ). Experimental evidence indicates that amylose is not a straight chain of glucose units but instead is coiled like a spring, with six glucose monomers per turn (part (b) of Figure 16.9 "Amylose" ). When coiled in this fashion, amylose has just enough room in its core to accommodate an iodine molecule. The characteristic blue-violet color that appears when starch is treated with iodine is due to the formation of the amylose-iodine complex. This color test is sensitive enough to detect even minute amounts of starch in solution. Figure 16.9 Amylose (a) Amylose is a linear chain of α-D-glucose units joined together by α-1,4-glycosidic bonds. (b) Because of hydrogen bonding, amylose acquires a spiral structure that contains six glucose units per turn. Amylopectin is a branched-chain polysaccharide composed of glucose units linked primarily by α-1,4-glycosidic bonds but with occasional α-1,6-glycosidic bonds, which are responsible for the branching. A molecule of amylopectin may contain many thousands of glucose units with branch points occurring about every 25–30 units ( Figure 16.10 "Representation of the Branching in Amylopectin and Glycogen" ). The helical structure of amylopectin is disrupted by the branching of the chain, so instead of the deep blue-violet color amylose gives with iodine, amylopectin produces a less intense reddish brown. Figure 16.10 Representation of the Branching in Amylopectin and Glycogen Both amylopectin and glycogen contain branch points that are linked through α-1,6-linkages. These branch points occur more often in glycogen. Dextrins are glucose polysaccharides of intermediate size. The shine and stiffness imparted to clothing by starch are due to the presence of dextrins formed when clothing is ironed. Because of their characteristic stickiness with wetting, dextrins are used as adhesives on stamps, envelopes, and labels; as binders to hold pills and tablets together; and as pastes. Dextrins are more easily digested than starch and are therefore used extensively in the commercial preparation of infant foods. The complete hydrolysis of starch yields, in successive stages, glucose: starch → dextrins → maltose → glucose In the human body, several enzymes known collectively as amylases degrade starch sequentially into usable glucose units. Glycogen Glycogen is the energy reserve carbohydrate of animals. Practically all mammalian cells contain some stored carbohydrates in the form of glycogen, but it is especially abundant in the liver (4%–8% by weight of tissue) and in skeletal muscle cells (0.5%–1.0%). Like starch in plants, glycogen is found as granules in liver and muscle cells. When fasting, animals draw on these glycogen reserves during the first day without food to obtain the glucose needed to maintain metabolic balance. Note About 70% of the total glycogen in the body is stored in muscle cells. Although the percentage of glycogen (by weight) is higher in the liver, the much greater mass of skeletal muscle stores a greater total amount of glycogen. Glycogen is structurally quite similar to amylopectin, although glycogen is more highly branched (8–12 glucose units between branches) and the branches are shorter. When treated with iodine, glycogen gives a reddish brown color. Glycogen can be broken down into its D-glucose subunits by acid hydrolysis or by the same enzymes that catalyze the breakdown of starch. In animals, the enzyme phosphorylase catalyzes the breakdown of glycogen to phosphate esters of glucose. Cellulose Cellulose, a fibrous carbohydrate found in all plants, is the structural component of plant cell walls. Because the earth is covered with vegetation, cellulose is the most abundant of all carbohydrates, accounting for over 50% of all the carbon found in the vegetable kingdom. Cotton fibrils and filter paper are almost entirely cellulose (about 95%), wood is about 50% cellulose, and the dry weight of leaves is about 10%–20% cellulose. The largest use of cellulose is in the manufacture of paper and paper products. Although the use of noncellulose synthetic fibers is increasing, rayon (made from cellulose) and cotton still account for over 70% of textile production. Like amylose, cellulose is a linear polymer of glucose. It differs, however, in that the glucose units are joined by β-1,4-glycosidic linkages, producing a more extended structure than amylose (part (a) of Figure 16.11 "Cellulose" ). This extreme linearity allows a great deal of hydrogen bonding between OH groups on adjacent chains, causing them to pack closely into fibers (part (b) of Figure 16.11 "Cellulose" ). As a result, cellulose exhibits little interaction with water or any other solvent. Cotton and wood, for example, are completely insoluble in water and have considerable mechanical strength. Because cellulose does not have a helical structure, it does not bind to iodine to form a colored product. Figure 16.11 Cellulose (a) There is extensive hydrogen bonding in the structure of cellulose. (b) In this electron micrograph of the cell wall of an alga, the wall consists of successive layers of cellulose fibers in parallel arrangement. Cellulose yields D-glucose after complete acid hydrolysis, yet humans are unable to metabolize cellulose as a source of glucose. Our digestive juices lack enzymes that can hydrolyze the β-glycosidic linkages found in cellulose, so although we can eat potatoes, we cannot eat grass. However, certain microorganisms can digest cellulose because they make the enzyme cellulase, which catalyzes the hydrolysis of cellulose. The presence of these microorganisms in the digestive tracts of herbivorous animals (such as cows, horses, and sheep) allows these animals to degrade the cellulose from plant material into glucose for energy. Termites also contain cellulase-secreting microorganisms and thus can subsist on a wood diet. This example once again demonstrates the extreme stereospecificity of biochemical processes. Career Focus: Certified Diabetes Educator Certified diabetes educators come from a variety of health professions, such as nursing and dietetics, and specialize in the education and treatment of patients with diabetes. A diabetes educator will work with patients to manage their diabetes. This involves teaching the patient to monitor blood sugar levels, make good food choices, develop and maintain an exercise program, and take medication, if required. Diabetes educators also work with hospital or nursing home staff to improve the care of diabetic patients. Educators must be willing to spend time attending meetings and reading the current literature to maintain their knowledge of diabetes medications, nutrition, and blood monitoring devices so that they can pass this information to their patients. © Thinkstock Answers Starch is the storage form of glucose (energy) in plants, while cellulose is a structural component of the plant cell wall. Glycogen is the storage form of glucose (energy) in animals. Key Takeaways Starch is a storage form of energy in plants. It contains two polymers composed of glucose units: amylose (linear) and amylopectin (branched). Glycogen is a storage form of energy in animals. It is a branched polymer composed of glucose units. It is more highly branched than amylopectin. Cellulose is a structural polymer of glucose units found in plants. It is a linear polymer with the glucose units linked through β-1,4-glycosidic bonds. Exercises What monosaccharide is obtained from the hydrolysis of each carbohydrate? starch cellulose glycogen For each carbohydrate listed in Exercise 1, indicate whether it is found in plants or mammals. Describe the similarities and differences between amylose and cellulose. Describe the similarities and differences between amylopectin and glycogen. Answers glucose glucose glucose Amylose and cellulose are both linear polymers of glucose units, but the glycosidic linkages between the glucose units differ. The linkages in amylose are α-1,4-glycosidic linkages, while the linkages in cellulose they are β-1,4-glycosidic linkages.	msmarco_doc_00_11971861
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s20-03-membranes-and-membrane-lipids.html	Membranes and Membrane Lipids	17.3 Membranes and Membrane Lipids 17.3 Membranes and Membrane Lipids Learning Objectives Membrane Proteins Answers Key Takeaways Exercises Answers	Membranes and Membrane Lipids 17.3 Membranes and Membrane Lipids Learning Objectives Identify the distinguishing characteristics of membrane lipids. Describe membrane components and how they are arranged. All living cells are surrounded by a cell membrane. Plant cells ( Figure 17.3 "An Idealized Plant Cell") and animal cells ( Figure 17.4 "An Idealized Animal Cell") contain a cell nucleus that is also surrounded by a membrane and holds the genetic information for the cell. (For more information about genetics and DNA, see Chapter 19 "Nucleic Acids" .) Everything between the cell membrane and the nuclear membrane—including intracellular fluids and various subcellular components such as the mitochondria and ribosomes—is called the cytoplasm Everything between the cell membrane and the nuclear membrane. . The membranes of all cells have a fundamentally similar structure, but membrane function varies tremendously from one organism to another and even from one cell to another within a single organism. This diversity arises mainly from the presence of different proteins and lipids in the membrane. Figure 17.3 An Idealized Plant Cell Not all the structures shown here occur in every type of plant cell. Figure 17.4 An Idealized Animal Cell The structures shown here will seldom all be found in a single animal cell. The lipids in cell membranes are highly polar but have dual characteristics: part of the lipid is ionic and therefore dissolves in water, whereas the rest has a hydrocarbon structure and therefore dissolves in nonpolar substances. Often, the ionic part is referred to as hydrophilic Having an affinity for water; “water loving.” , meaning “water loving,” and the nonpolar part as hydrophobic Not having an affinity for water; “water fearing.” , meaning “water fearing” (repelled by water). When allowed to float freely in water, polar lipids spontaneously cluster together in any one of three arrangements: micelles, monolayers, and bilayers ( Figure 17.5 "Spontaneously Formed Polar Lipid Structures in Water: Monolayer, Micelle, and Bilayer" ). Micelles An aggregation in which a nonpolar tail is directed toward the center of the structure and the polar head is directed outward. are aggregations in which the lipids’ hydrocarbon tails—being hydrophobic—are directed toward the center of the assemblage and away from the surrounding water while the hydrophilic heads are directed outward, in contact with the water. Each micelle may contain thousands of lipid molecules. Polar lipids may also form a monolayer, a layer one molecule thick on the surface of the water. The polar heads face into water, and the nonpolar tails stick up into the air. Bilayers A double layer of lipids arranged so that nonpolar tails are found between an inner surface and outer surface consisting of hydrophilic heads. are double layers of lipids arranged so that the hydrophobic tails are sandwiched between an inner surface and an outer surface consisting of hydrophilic heads. The hydrophilic heads are in contact with water on either side of the bilayer, whereas the tails, sequestered inside the bilayer, are prevented from having contact with the water. Bilayers like this make up every cell membrane ( Figure 17.6 "Schematic Diagram of a Cell Membrane" ). Figure 17.5 Spontaneously Formed Polar Lipid Structures in Water: Monolayer, Micelle, and Bilayer Figure 17.6 Schematic Diagram of a Cell Membrane The membrane enclosing a typical animal cell is a phospholipid bilayer with embedded cholesterol and protein molecules. Short oligosaccharide chains are attached to the outer surface. In the bilayer interior, the hydrophobic tails (that is, the fatty acid portions of lipid molecules) interact by means of dispersion forces. The interactions are weakened by the presence of unsaturated fatty acids. As a result, the membrane components are free to mill about to some extent, and the membrane is described as fluid. The lipids found in cell membranes can be categorized in various ways. Phospholipids A lipid containing phosphorus. are lipids containing phosphorus. Glycolipids A sugar-containing lipid. are sugar-containing lipids. The latter are found exclusively on the outer surface of the cell membrane, acting as distinguishing surface markers for the cell and thus serving in cellular recognition and cell-to-cell communication. Sphingolipids A lipid that contains the unsaturated amino alcohol sphingosine. are phospholipids or glycolipids that contain the unsaturated amino alcohol sphingosine rather than glycerol. Diagrammatic structures of representative membrane lipids are presented in Figure 17.7 "Component Structures of Some Important Membrane Lipids". Figure 17.7 Component Structures of Some Important Membrane Lipids Phosphoglycerides (also known as glycerophospholipids) are the most abundant phospholipids in cell membranes. They consist of a glycerol unit with fatty acids attached to the first two carbon atoms, while a phosphoric acid unit, esterified with an alcohol molecule (usually an amino alcohol, as in part (a) of Figure 17.8 "Phosphoglycerides") is attached to the third carbon atom of glycerol (part (b) of Figure 17.8 "Phosphoglycerides" ). Notice that the phosphoglyceride molecule is identical to a triglyceride up to the phosphoric acid unit (part (b) of Figure 17.8 "Phosphoglycerides" ). Figure 17.8 Phosphoglycerides (a) Amino alcohols are commonly found in phosphoglycerides, which are evident in its structural formula (b). There are two common types of phosphoglycerides. Phosphoglycerides containing ethanolamine as the amino alcohol are called phosphatidylethanolamines or cephalins. Cephalins are found in brain tissue and nerves and also have a role in blood clotting. Phosphoglycerides containing choline as the amino alcohol unit are called phosphatidylcholines or lecithins. Lecithins occur in all living organisms. Like cephalins, they are important constituents of nerve and brain tissue. Egg yolks are especially rich in lecithins. Commercial-grade lecithins isolated from soybeans are widely used in foods as emulsifying agents. An emulsifying agent is used to stabilize an emulsion A dispersion of two liquids that do not normally mix. —a dispersion of two liquids that do not normally mix, such as oil and water. Many foods are emulsions. Milk is an emulsion of butterfat in water. The emulsifying agent in milk is a protein called casein. Mayonnaise is an emulsion of salad oil in water, stabilized by lecithins present in egg yolk. Sphingomyelins A sphingolipid that contains a fatty acid unit, a phosphoric acid unit, a sphingosine unit, and a choline unit. , the simplest sphingolipids, each contain a fatty acid, a phosphoric acid, sphingosine, and choline ( Figure 17.9 "Sphingolipids" ). Because they contain phosphoric acid, they are also classified as phospholipids. Sphingomyelins are important constituents of the myelin sheath surrounding the axon of a nerve cell. Multiple sclerosis is one of several diseases resulting from damage to the myelin sheath. Figure 17.9 Sphingolipids (a) Sphingosine, an amino alcohol, is found in all sphingolipids. (b) A sphingomyelin is also known as a phospholipid, as evidenced by the phosphoric acid unit in its structure. Most animal cells contain sphingolipids called cerebrosides A sphingolipid that contains a fatty acid unit, a sphingosine unit, and galactose or glucose. ( Figure 17.10 "Cerebrosides" ). Cerebrosides are composed of sphingosine, a fatty acid, and galactose or glucose. They therefore resemble sphingomyelins but have a sugar unit in place of the choline phosphate group. Cerebrosides are important constituents of the membranes of nerve and brain cells. Figure 17.10 Cerebrosides Cerebrosides are sphingolipids that contain a sugar unit. The sphingolipids called gangliosides A sphingolipid that contains a fatty acid unit, a sphingosine unit, and a complex oligosaccharide. are more complex, usually containing a branched chain of three to eight monosaccharides and/or substituted sugars. Because of considerable variation in their sugar components, about 130 varieties of gangliosides have been identified. Most cell-to-cell recognition and communication processes (e.g., blood group antigens) depend on differences in the sequences of sugars in these compounds. Gangliosides are most prevalent in the outer membranes of nerve cells, although they also occur in smaller quantities in the outer membranes of most other cells. Because cerebrosides and gangliosides contain sugar groups, they are also classified as glycolipids. Membrane Proteins If membranes were composed only of lipids, very few ions or polar molecules could pass through their hydrophobic “sandwich filling” to enter or leave any cell. However, certain charged and polar species do cross the membrane, aided by proteins that move about in the lipid bilayer. The two major classes of proteins in the cell membrane are integral proteins A protein that spans the lipids bilayer of membranes. , which span the hydrophobic interior of the bilayer, and peripheral proteins A protein that is more loosely associated with the membrane surface. , which are more loosely associated with the surface of the lipid bilayer ( Figure 17.6 "Schematic Diagram of a Cell Membrane" ). Peripheral proteins may be attached to integral proteins, to the polar head groups of phospholipids, or to both by hydrogen bonding and electrostatic forces. Small ions and molecules soluble in water enter and leave the cell by way of channels through the integral proteins. Some proteins, called carrier proteins, facilitate the passage of certain molecules, such as hormones and neurotransmitters, by specific interactions between the protein and the molecule being transported. Answers a phosphate group a saccharide unit (monosaccharide or more complex) sphingosine The dual character is critical for the formation of the lipid bilayer. The hydrophilic portions of the molecule are in contact with the aqueous environment of the cell, while the hydrophobic portion of the lipids is in the interior of the bilayer and provides a barrier to the passive diffusion of most molecules. Lecithin acts as an emulsifying agent that aids in the mixing of the hot cocoa mix with water and keeps the cocoa mix evenly distributed after stirring. Key Takeaways Lipids are important components of biological membranes. These lipids have dual characteristics: part of the molecule is hydrophilic, and part of the molecule is hydrophobic. Membrane lipids may be classified as phospholipids, glycolipids, and/or sphingolipids. Proteins are another important component of biological membranes. Integral proteins span the lipid bilayer, while peripheral proteins are more loosely associated with the surface of the membrane. Exercises Classify each as a phospholipid, a glycolipid, and/or a sphingolipid. (Some lipids can be given more than one classification.) Classify each as a phospholipid, a glycolipid, and/or a sphingolipid. (Some lipids can be given more than one classification.) Draw the structure of the sphingomyelin that has lauric acid as its fatty acid and ethanolamine as its amino alcohol. Draw the structure of the cerebroside that has myristic acid as its fatty acid and galactose as its sugar. Distinguish between an integral protein and a peripheral protein. What is one key function of integral proteins? Answers phospholipid sphingolipid and glycolipid Integral proteins span the lipid bilayer, while peripheral proteins associate with the surfaces of the lipid bilayer. aid in the movement of charged and polar species across the membrane	msmarco_doc_00_11982538
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s21-02-reactions-of-amino-acids.html	Reactions of Amino Acids	18.2 Reactions of Amino Acids 18.2 Reactions of Amino Acids Learning Objective Example 1 Skill-Building Exercise Answers Key Takeaways Exercises Answer	Reactions of Amino Acids 18.2 Reactions of Amino Acids Learning Objective Explain how an amino acid can act as both an acid and a base. The structure of an amino acid allows it to act as both an acid and a base. An amino acid has this ability because at a certain pH value (different for each amino acid) nearly all the amino acid molecules exist as zwitterions. If acid is added to a solution containing the zwitterion, the carboxylate group captures a hydrogen (H +) ion, and the amino acid becomes positively charged. If base is added, ion removal of the H + ion from the amino group of the zwitterion produces a negatively charged amino acid. In both circumstances, the amino acid acts to maintain the pH of the system—that is, to remove the added acid (H +) or base (OH −) from solution. Example 1 Draw the structure for the anion formed when glycine (at neutral pH) reacts with a base. Draw the structure for the cation formed when glycine (at neutral pH) reacts with an acid. Solution The base removes H + from the protonated amine group. The acid adds H + to the carboxylate group. Skill-Building Exercise Draw the structure for the cation formed when valine (at neutral pH) reacts with an acid. Draw the structure for the anion formed when valine (at neutral pH) reacts with a base. The particular pH at which a given amino acid exists in solution as a zwitterion is called the isoelectric point The pH at which a given amino acid exists in solution as a zwitterion. (pI). At its pI, the positive and negative charges on the amino acid balance, and the molecule as a whole is electrically neutral. The amino acids whose side chains are always neutral have isoelectric points ranging from 5.0 to 6.5. The basic amino acids (which have positively charged side chains at neutral pH) have relatively high pIs. Acidic amino acids (which have negatively charged side chains at neutral pH) have quite low pIs ( Table 18.3 "pIs of Some Representative Amino Acids" ). Table 18.3 pIs of Some Representative Amino Acids Amino Acid Classification pI alanine nonpolar 6.0 valine nonpolar 6.0 serine polar, uncharged 5.7 threonine polar, uncharged 6.5 arginine positively charged (basic) 10.8 histidine positively charged (basic) 7.6 lysine positively charged (basic) 9.8 aspartic acid negatively charged (acidic) 3.0 glutamic acid negatively charged (acidic) 3.2 Amino acids undergo reactions characteristic of carboxylic acids and amines. The reactivity of these functional groups is particularly important in linking amino acids together to form peptides and proteins, as you will see later in this chapter. Simple chemical tests that are used to detect amino acids take advantage of the reactivity of these functional groups. An example is the ninhydrin test in which the amine functional group of α-amino acids reacts with ninhydrin to form purple-colored compounds. Ninhydrin is used to detect fingerprints because it reacts with amino acids from the proteins in skin cells transferred to the surface by the individual leaving the fingerprint. Answers an electrically neutral compound that contains both negatively and positively charged groups the pH at which a given amino acid exists in solution as a zwitterion Key Takeaways Amino acids can act as both an acid and a base due to the presence of the amino and carboxyl functional groups. The pH at which a given amino acid exists in solution as a zwitterion is called the isoelectric point (pI). Exercises Draw the structure of leucine and determine the charge on the molecule in a (n) acidic solution (pH = 1). neutral solution (pH = 7). a basic solution (pH = 11) Draw the structure of isoleucine and determine the charge on the molecule in a (n) acidic solution (pH = 1). neutral solution (pH = 7). basic solution (pH = 11). Answer	msmarco_doc_00_11994765
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s21-05-enzymes.html	Enzymes	18.5 Enzymes 18.5 Enzymes Learning Objectives Answers Key Takeaways Exercises Answers	Enzymes 18.5 Enzymes Learning Objectives Explain the functions of enzymes. Explain how enzymes are classified and named. A catalyst Any substance that increases the rate or speed of a chemical reaction without being changed or consumed in the reaction. is any substance that increases the rate or speed of a chemical reaction without being changed or consumed in the reaction. Enzymes A biological catalyst. are biological catalysts, and nearly all of them are proteins. The reaction rates attained by enzymes are truly amazing. In their presence, reactions occur at rates that are a million (10 6) or more times faster than would be attainable in their absence. What is even more amazing is that enzymes perform this function at body temperature (~37°C) and physiological pH (pH ~7), rather than at the conditions that are typically necessary to increase reaction rates (high temperature or pressure, the use of strong oxidizing or reducing agents or strong acids or bases, or a combination of any of these). In addition, enzymes are highly specific in their action; that is, each enzyme catalyzes only one type of reaction in only one compound or a group of structurally related compounds. The compound or compounds on which an enzyme acts are known as its substrates A compound on which an enzyme acts. . Hundreds of enzymes have been purified and studied in an effort to understand how they work so effectively and with such specificity. The resulting knowledge has been used to design drugs that inhibit or activate particular enzymes. An example is the intensive research to improve the treatment of or find a cure for acquired immunodeficiency syndrome (AIDS). AIDS is caused by the human immunodeficiency virus (HIV). Researchers are studying the enzymes produced by this virus and are developing drugs intended to block the action of those enzymes without interfering with enzymes produced by the human body. Several of these drugs have now been approved for use by AIDS patients. The first enzymes to be discovered were named according to their source or method of discovery. The enzyme pepsin, which aids in the hydrolysis of proteins, is found in the digestive juices of the stomach (Greek pepsis, meaning “digestion”). Papain, another enzyme that hydrolyzes protein (in fact, it is used in meat tenderizers), is isolated from papayas. As more enzymes were discovered, chemists recognized the need for a more systematic and chemically informative identification scheme. In the current numbering and naming scheme, under the oversight of the Nomenclature Commission of the International Union of Biochemistry, enzymes are arranged into six groups according to the general type of reaction they catalyze ( Table 18.5 "Classes of Enzymes" ), with subgroups and secondary subgroups that specify the reaction more precisely. Each enzyme is assigned a four-digit number, preceded by the prefix EC—for enzyme classification—that indicates its group, subgroup, and so forth. This is demonstrated in Table 18.6 "Assignment of an Enzyme Classification Number" for alcohol dehydrogenase. Each enzyme is also given a name consisting of the root of the name of its substrate or substrates and the - ase suffix. Thus urease is the enzyme that catalyzes the hydrolysis of urea. Table 18.5 Classes of Enzymes Class Type of Reaction Catalyzed Examples oxidoreductases oxidation-reduction reactions Dehydrogenases catalyze oxidation-reduction reactions involving hydrogen and reductases catalyze reactions in which a substrate is reduced. transferases transfer reactions of groups, such as methyl, amino, and acetyl Transaminases catalyze the transfer of amino group, and kinases catalyze the transfer of a phosphate group. hydrolases hydrolysis reactions Lipases catalyze the hydrolysis of lipids, and proteases catalyze the hydrolysis of proteins lyases reactions in which groups are removed without hydrolysis or addition of groups to a double bond Decarboxylases catalyze the removal of carboxyl groups. isomerases reactions in which a compound is converted to its isomer Isomerases may catalyze the conversion of an aldose to a ketose, and mutases catalyze reactions in which a functional group is transferred from one atom in a substrate to another. ligases reactions in which new bonds are formed between carbon and another atom; energy is required Synthetases catalyze reactions in which two smaller molecules are linked to form a larger one. Table 18.6 Assignment of an Enzyme Classification Number Alcohol Dehydrogenase: EC 1.1.1.1 The first digit indicates that this enzyme is an oxidoreductase; that is, an enzyme that catalyzes an oxidation-reduction reaction. The second digit indicates that this oxidoreductase catalyzes a reaction involving a primary or secondary alcohol. The third digit indicates that either the coenzyme NAD + or NADP + is required for this reaction. The fourth digit indicates that this was the first enzyme isolated, characterized, and named using this system of nomenclature. The systematic name for this enzyme is alcohol:NAD+ oxidoreductase, while the recommended or common name is alcohol dehydrogenase. Reaction catalyzed: Answers sucrose sucrase Key Takeaways An enzyme is a biological catalyst, a substance that increases the rate of a chemical reaction without being changed or consumed in the reaction. A systematic process is used to name and classify enzymes. Exercises Identify the substrate catalyzed by each enzyme. lactase cellulase peptidase Identify the substrate catalyzed by each enzyme. lipase amylase maltase Identify each type of enzyme. decarboxylase protease transaminase Identify each type of enzyme. dehydrogenase isomerase lipase Answers lactose cellulose peptides lyase hydrolase transferase	msmarco_doc_00_11999043
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s21-06-enzyme-action.html	Enzyme Action	18.6 Enzyme Action 18.6 Enzyme Action Learning Objective Example 1 Skill-Building Exercise Answers Key Takeaways Exercises Answers	Enzyme Action 18.6 Enzyme Action Learning Objective Describe the interaction between an enzyme and its substrate. Enzyme-catalyzed reactions occur in at least two steps. In the first step, an enzyme molecule (E) and the substrate molecule or molecules (S) collide and react to form an intermediate compound called the enzyme-substrate (E–S) complex. (This step is reversible because the complex can break apart into the original substrate or substrates and the free enzyme.) Once the E–S complex forms, the enzyme is able to catalyze the formation of product (P), which is then released from the enzyme surface: S + E → E–S E–S → P + E Hydrogen bonding and other electrostatic interactions hold the enzyme and substrate together in the complex. The structural features or functional groups on the enzyme that participate in these interactions are located in a cleft or pocket on the enzyme surface. This pocket, where the enzyme combines with the substrate and transforms the substrate to product is called the active site The location on an enzyme where a substrate binds and is transformed to product. of the enzyme ( Figure 18.10 "Substrate Binding to the Active Site of an Enzyme" ). It possesses a unique conformation (including correctly positioned bonding groups) that is complementary to the structure of the substrate, so that the enzyme and substrate molecules fit together in much the same manner as a key fits into a tumbler lock. In fact, an early model describing the formation of the enzyme-substrate complex was called the lock-and-key model A model that portrays an enzyme as conformationally rigid and able to bond only to a substrate or substrates that exactly fit the active site. ( Figure 18.11 "The Lock-and-Key Model of Enzyme Action" ). This model portrayed the enzyme as conformationally rigid and able to bond only to substrates that exactly fit the active site. Figure 18.10 Substrate Binding to the Active Site of an Enzyme The enzyme dihydrofolate reductase is shown with one of its substrates: NADP + (a) unbound and (b) bound. The NADP + (shown in red) binds to a pocket that is complementary to it in shape and ionic properties. Figure 18.11 The Lock-and-Key Model of Enzyme Action (a) Because the substrate and the active site of the enzyme have complementary structures and bonding groups, they fit together as a key fits a lock. (b) The catalytic reaction occurs while the two are bonded together in the enzyme-substrate complex. Working out the precise three-dimensional structures of numerous enzymes has enabled chemists to refine the original lock-and-key model of enzyme actions. They discovered that the binding of a substrate often leads to a large conformational change in the enzyme, as well as to changes in the structure of the substrate or substrates. The current theory, known as the induced-fit model A model that says an enzyme can undergo a conformational change when it binds substrate molecules. , says that enzymes can undergo a change in conformation when they bind substrate molecules, and the active site has a shape complementary to that of the substrate only after the substrate is bound, as shown for hexokinase in Figure 18.12 "The Induced-Fit Model of Enzyme Action". After catalysis, the enzyme resumes its original structure. Figure 18.12 The Induced-Fit Model of Enzyme Action (a) The enzyme hexokinase without its substrate (glucose, shown in red) is bound to the active site. (b) The enzyme conformation changes dramatically when the substrate binds to it, resulting in additional interactions between hexokinase and glucose. The structural changes that occur when an enzyme and a substrate join together bring specific parts of a substrate into alignment with specific parts of the enzyme’s active site. Amino acid side chains in or near the binding site can then act as acid or base catalysts, provide binding sites for the transfer of functional groups from one substrate to another or aid in the rearrangement of a substrate. The participating amino acids, which are usually widely separated in the primary sequence of the protein, are brought close together in the active site as a result of the folding and bending of the polypeptide chain or chains when the protein acquires its tertiary and quaternary structure. Binding to enzymes brings reactants close to each other and aligns them properly, which has the same effect as increasing the concentration of the reacting compounds. Example 1 What type of interaction would occur between an OH group present on a substrate molecule and a functional group in the active site of an enzyme? Suggest an amino acid whose side chain might be in the active site of an enzyme and form the type of interaction you just identified. Solution An OH group would most likely engage in hydrogen bonding with an appropriate functional group present in the active site of an enzyme. Several amino acid side chains would be able to engage in hydrogen bonding with an OH group. One example would be asparagine, which has an amide functional group. Skill-Building Exercise What type of interaction would occur between an COO − group present on a substrate molecule and a functional group in the active site of an enzyme? Suggest an amino acid whose side chain might be in the active site of an enzyme and form the type of interaction you just identified. One characteristic that distinguishes an enzyme from all other types of catalysts is its substrate specificity. An inorganic acid such as sulfuric acid can be used to increase the reaction rates of many different reactions, such as the hydrolysis of disaccharides, polysaccharides, lipids, and proteins, with complete impartiality. In contrast, enzymes are much more specific. Some enzymes act on a single substrate, while other enzymes act on any of a group of related molecules containing a similar functional group or chemical bond. Some enzymes even distinguish between D- and L-stereoisomers, binding one stereoisomer but not the other. Urease, for example, is an enzyme that catalyzes the hydrolysis of a single substrate—urea—but not the closely related compounds methyl urea, thiourea, or biuret. The enzyme carboxypeptidase, on the other hand, is far less specific. It catalyzes the removal of nearly any amino acid from the carboxyl end of any peptide or protein. Enzyme specificity results from the uniqueness of the active site in each different enzyme because of the identity, charge, and spatial orientation of the functional groups located there. It regulates cell chemistry so that the proper reactions occur in the proper place at the proper time. Clearly, it is crucial to the proper functioning of the living cell. Answers The lock-and-key model portrays an enzyme as conformationally rigid and able to bond only to substrates that exactly fit the active site. The induced fit model portrays the enzyme structure as more flexible and is complementary to the substrate only after the substrate is bound. Urease has the greater specificity because it can bind only to a single substrate. Carboxypeptidase, on the other hand, can catalyze the removal of nearly any amino acid from the carboxyl end of a peptide or protein. Key Takeaways A substrate binds to a specific region on an enzyme known as the active site, where the substrate can be converted to product. The substrate binds to the enzyme primarily through hydrogen bonding and other electrostatic interactions. The induced-fit model says that an enzyme can undergo a conformational change when binding a substrate. Enzymes exhibit varying degrees of substrate specificity. Exercises What type of interaction would occur between each group present on a substrate molecule and a functional group of the active site in an enzyme? COOH NH 3+ OH CH (CH 3) 2 What type of interaction would occur between each group present on a substrate molecule and a functional group of the active site in an enzyme? SH NH 2 C 6 H 5 COO − For each functional group in Exercise 1, suggest an amino acid whose side chain might be in the active site of an enzyme and form the type of interaction you identified. For each functional group in Exercise 2, suggest an amino acid whose side chain might be in the active site of an enzyme and form the type of interaction you identified. Answers hydrogen bonding ionic bonding hydrogen bonding dispersion forces The amino acid has a polar side chain capable of engaging in hydrogen bonding; serine (answers will vary). The amino acid has a negatively charged side chain; aspartic acid (answers will vary). The amino acid has a polar side chain capable of engaging in hydrogen bonding; asparagine (answers will vary). The amino acid has a nonpolar side chain; isoleucine (answers will vary).	msmarco_doc_00_12005206
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s21-07-enzyme-activity.html	Enzyme Activity	18.7 Enzyme Activity 18.7 Enzyme Activity Learning Objective Concentration of Substrate Concentration of Enzyme Temperature Hydrogen Ion Concentration (pH) Answers Key Takeaways Exercises Answers	Enzyme Activity 18.7 Enzyme Activity Learning Objective Describe how pH, temperature, and the concentration of an enzyme and its substrate influence enzyme activity. The single most important property of enzymes is the ability to increase the rates of reactions occurring in living organisms, a property known as catalytic activity. Because most enzymes are proteins, their activity is affected by factors that disrupt protein structure, as well as by factors that affect catalysts in general. Factors that disrupt protein structure, as we saw in Section 18.4 "Proteins", include temperature and pH; factors that affect catalysts in general include reactant or substrate concentration and catalyst or enzyme concentration. The activity of an enzyme can be measured by monitoring either the rate at which a substrate disappears or the rate at which a product forms. Concentration of Substrate In the presence of a given amount of enzyme, the rate of an enzymatic reaction increases as the substrate concentration increases until a limiting rate is reached, after which further increase in the substrate concentration produces no significant change in the reaction rate (part (a) of Figure 18.13 "Concentration versus Reaction Rate" ). At this point, so much substrate is present that essentially all of the enzyme active sites have substrate bound to them. In other words, the enzyme molecules are saturated with substrate. The excess substrate molecules cannot react until the substrate already bound to the enzymes has reacted and been released (or been released without reacting). Figure 18.13 Concentration versus Reaction Rate (a) This graph shows the effect of substrate concentration on the rate of a reaction that is catalyzed by a fixed amount of enzyme. (b) This graph shows the effect of enzyme concentration on the reaction rate at a constant level of substrate. Let’s consider an analogy. Ten taxis (enzyme molecules) are waiting at a taxi stand to take people (substrate) on a 10-minute trip to a concert hall, one passenger at a time. If only 5 people are present at the stand, the rate of their arrival at the concert hall is 5 people in 10 minutes. If the number of people at the stand is increased to 10, the rate increases to 10 arrivals in 10 minutes. With 20 people at the stand, the rate would still be 10 arrivals in 10 minutes. The taxis have been “saturated.” If the taxis could carry 2 or 3 passengers each, the same principle would apply. The rate would simply be higher (20 or 30 people in 10 minutes) before it leveled off. Concentration of Enzyme When the concentration of the enzyme is significantly lower than the concentration of the substrate (as when the number of taxis is far lower than the number of waiting passengers), the rate of an enzyme-catalyzed reaction is directly dependent on the enzyme concentration (part (b) of Figure 18.13 "Concentration versus Reaction Rate" ). This is true for any catalyst; the reaction rate increases as the concentration of the catalyst is increased. Temperature A general rule of thumb for most chemical reactions is that a temperature rise of 10°C approximately doubles the reaction rate. To some extent, this rule holds for all enzymatic reactions. After a certain point, however, an increase in temperature causes a decrease in the reaction rate, due to denaturation of the protein structure and disruption of the active site (part (a) of Figure 18.14 "Temperature and pH versus Concentration" ). For many proteins, denaturation occurs between 45°C and 55°C. Furthermore, even though an enzyme may appear to have a maximum reaction rate between 40°C and 50°C, most biochemical reactions are carried out at lower temperatures because enzymes are not stable at these higher temperatures and will denature after a few minutes. Figure 18.14 Temperature and pH versus Concentration (a) This graph depicts the effect of temperature on the rate of a reaction that is catalyzed by a fixed amount of enzyme. (b) This graph depicts the effect of pH on the rate of a reaction that is catalyzed by a fixed amount of enzyme. At 0°C and 100°C, the rate of enzyme-catalyzed reactions is nearly zero. This fact has several practical applications. We sterilize objects by placing them in boiling water, which denatures the enzymes of any bacteria that may be in or on them. We preserve our food by refrigerating or freezing it, which slows enzyme activity. When animals go into hibernation in winter, their body temperature drops, decreasing the rates of their metabolic processes to levels that can be maintained by the amount of energy stored in the fat reserves in the animals’ tissues. Hydrogen Ion Concentration (pH) Because most enzymes are proteins, they are sensitive to changes in the hydrogen ion concentration or pH. Enzymes may be denatured by extreme levels of hydrogen ions (whether high or low); any change in pH, even a small one, alters the degree of ionization of an enzyme’s acidic and basic side groups and the substrate components as well. Ionizable side groups located in the active site must have a certain charge for the enzyme to bind its substrate. Neutralization of even one of these charges alters an enzyme’s catalytic activity. An enzyme exhibits maximum activity over the narrow pH range in which a molecule exists in its properly charged form. The median value of this pH range is called the optimum pH The pH at which a particular enzyme exhibits maximum activity. of the enzyme (part (b) of Figure 18.14 "Temperature and pH versus Concentration" ). With the notable exception of gastric juice (the fluids secreted in the stomach), most body fluids have pH values between 6 and 8. Not surprisingly, most enzymes exhibit optimal activity in this pH range. However, a few enzymes have optimum pH values outside this range. For example, the optimum pH for pepsin, an enzyme that is active in the stomach, is 2.0. Answers If the concentration of the substrate is low, increasing its concentration will increase the rate of the reaction. An increase in the amount of enzyme will increase the rate of the reaction (provided sufficient substrate is present). Key Takeaways Initially, an increase in substrate concentration leads to an increase in the rate of an enzyme-catalyzed reaction. As the enzyme molecules become saturated with substrate, this increase in reaction rate levels off. The rate of an enzyme-catalyzed reaction increases with an increase in the concentration of an enzyme. At low temperatures, an increase in temperature increases the rate of an enzyme-catalyzed reaction. At higher temperatures, the protein is denatured, and the rate of the reaction dramatically decreases. An enzyme has an optimum pH range in which it exhibits maximum activity. Exercises In non-enzyme-catalyzed reactions, the reaction rate increases as the concentration of reactant is increased. In an enzyme-catalyzed reaction, the reaction rate initially increases as the substrate concentration is increased but then begins to level off, so that the increase in reaction rate becomes less and less as the substrate concentration increases. Explain this difference. Why do enzymes become inactive at very high temperatures? An enzyme has an optimum pH of 7.4. What is most likely to happen to the activity of the enzyme if the pH drops to 6.3? Explain. An enzyme has an optimum pH of 7.2. What is most likely to happen to the activity of the enzyme if the pH increases to 8.5? Explain. Answers In an enzyme-catalyzed reaction, the substrate binds to the enzyme to form an enzyme-substrate complex. If more substrate is present than enzyme, all of the enzyme binding sites will have substrate bound, and further increases in substrate concentration cannot increase the rate. The activity will decrease; a pH of 6.3 is more acidic than 7.4, and one or more key groups in the active site may bind a hydrogen ion, changing the charge on that group.	msmarco_doc_00_12014438
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s21-09-enzyme-cofactors-and-vitamins.html	Enzyme Cofactors and Vitamins	18.9 Enzyme Cofactors and Vitamins 18.9 Enzyme Cofactors and Vitamins Learning Objective Note Answers Key Takeaways Exercises Answers	Enzyme Cofactors and Vitamins 18.9 Enzyme Cofactors and Vitamins Learning Objective Explain why vitamins are necessary in the diet. Many enzymes are simple proteins consisting entirely of one or more amino acid chains. Other enzymes contain a nonprotein component called a cofactor A nonprotein component of an enzyme that is necessary for an enzyme’s proper functioning. that is necessary for the enzyme’s proper functioning. There are two types of cofactors: inorganic ions [e.g., zinc or Cu (I) ions] and organic molecules known as coenzymes A cofactor that is an organic molecule. . Most coenzymes are vitamins or are derived from vitamins. Vitamins An organic compound that is essential in very small amounts for the maintenance of normal metabolism. are organic compounds that are essential in very small (trace) amounts for the maintenance of normal metabolism. They generally cannot be synthesized at adequate levels by the body and must be obtained from the diet. The absence or shortage of a vitamin may result in a vitamin-deficiency disease. In the first half of the 20th century, a major focus of biochemistry was the identification, isolation, and characterization of vitamins. Despite accumulating evidence that people needed more than just carbohydrates, fats, and proteins in their diets for normal growth and health, it was not until the early 1900s that research established the need for trace nutrients in the diet. Because organisms differ in their synthetic abilities, a substance that is a vitamin for one species may not be so for another. Over the past 100 years, scientists have identified and isolated 13 vitamins required in the human diet and have divided them into two broad categories: the fat-soluble vitamins, which include vitamins A, D, E, and K, and the water-soluble vitamins, which are the B complex vitamins and vitamin C. All fat-soluble vitamins contain a high proportion of hydrocarbon structural components. There are one or two oxygen atoms present, but the compounds as a whole are nonpolar. In contrast, water-soluble vitamins contain large numbers of electronegative oxygen and nitrogen atoms, which can engage in hydrogen bonding with water. Most water-soluble vitamins act as coenzymes or are required for the synthesis of coenzymes. The fat-soluble vitamins are important for a variety of physiological functions. The key vitamins and their functions are found in Table 18.8 "Fat-Soluble Vitamins and Physiological Functions" and Table 18.9 "Water-Soluble Vitamins and Physiological Functions". Table 18.8 Fat-Soluble Vitamins and Physiological Functions Vitamin Physiological Function Effect of Deficiency vitamin A (retinol) formation of vision pigments; differentiation of epithelial cells night blindness; continued deficiency leads to total blindness vitamin D (cholecalciferol) increases the body’s ability to absorb calcium and phosphorus osteomalacia (softening of the bones); known as rickets in children vitamin E (tocopherol) fat-soluble antioxidant damage to cell membranes vitamin K (phylloquinone) formation of prothrombin, a key enzyme in the blood-clotting process increases the time required for blood to clot Table 18.9 Water-Soluble Vitamins and Physiological Functions Vitamin Coenzyme Coenzyme Function Deficiency Disease vitamin B 1 (thiamine) thiamine pyrophosphate decarboxylation reactions beri-beri vitamin B 2 (riboflavin) flavin mononucleotide or flavin adenine dinucleotide oxidation-reduction reactions involving two hydrogen atoms — vitamin B 3 (niacin) nicotinamide adenine dinucleotide or nicotinamide adenine dinucleotide phosphate oxidation-reduction reactions involving the hydride ion (H −) pellagra vitamin B 6 (pyridoxine) pyridoxal phosphate variety of reactions including the transfer of amino groups — vitamin B 12 (cyanocobalamin) methylcobalamin or deoxyadenoxylcobalamin intramolecular rearrangement reactions pernicious anemia biotin biotin carboxylation reactions — folic acid tetrahydrofolate carrier of one-carbon units such as the formyl group anemia pantothenic Acid coenzyme A carrier of acyl groups — vitamin C (ascorbic acid) none antioxidant; formation of collagen, a protein found in tendons, ligaments, and bone scurvy Vitamins C and E, as well as the provitamin β-carotene can act as antioxidants in the body. Antioxidants A substance that prevents oxidation. prevent damage from free radicals, which are molecules that are highly reactive because they have unpaired electrons. Free radicals are formed not only through metabolic reactions involving oxygen but also by such environmental factors as radiation and pollution. Note β-carotene is known as a provitamin because it can be converted to vitamin A in the body. Free radicals react most commonly react with lipoproteins and unsaturated fatty acids in cell membranes, removing an electron from those molecules and thus generating a new free radical. The process becomes a chain reaction that finally leads to the oxidative degradation of the affected compounds. Antioxidants react with free radicals to stop these chain reactions by forming a more stable molecule or, in the case of vitamin E, a free radical that is much less reactive. (Vitamin E is converted back to its original form through interaction with vitamin C.) Answers A coenzyme is one type of cofactor. Coenzymes are organic molecules required by some enzymes for activity. A cofactor can be either a coenzyme or an inorganic ion. Coenzymes are synthesized from vitamins. Key Takeaways Vitamins are organic compounds that are essential in very small amounts for the maintenance of normal metabolism. Vitamins are divided into two broad categories: fat-soluble vitamins and water-soluble vitamins. Most water-soluble vitamins are needed for the formation of coenzymes, which are organic molecules needed by some enzymes for catalytic activity. Exercises Identify each vitamin as water soluble or fat soluble. vitamin D vitamin C vitamin B 12 Identify each vitamin as water soluble or fat soluble. niacin cholecalciferol biotin What vitamin is needed to form each coenzyme? pyridoxal phosphate flavin adenine dinucleotide coenzyme A nicotinamide adenine dinucleotide What coenzyme is formed from each vitamin? niacin thiamine cyanocobalamin pantothenic acid What is the function of each vitamin or coenzyme? flavin adenine dinucleotide vitamin A biotin What is the function of each vitamin or coenzyme? vitamin K pyridoxal phosphate tetrahydrofolate Answers fat soluble water soluble water soluble vitamin B 6 or pyridoxine vitamin B 2 or riboflavin pantothenic acid vitamin B 3 or niacin	msmarco_doc_00_12022912
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s22-03-replication-and-expression-of-.html	Replication and Expression of Genetic Information	19.3 Replication and Expression of Genetic Information 19.3 Replication and Expression of Genetic Information Learning Objectives Replication Example 1 Skill-Building Exercise Transcription Example 2 Skill-Building Exercise Answers Key Takeaways Exercises Answers	Replication and Expression of Genetic Information 19.3 Replication and Expression of Genetic Information Learning Objectives Describe how a new copy of DNA is synthesized. Describe how RNA is synthesized from DNA. Identify the different types of RNA and the function of each type of RNA. We previously stated that deoxyribonucleic acid (DNA) stores genetic information, while ribonucleic acid (RNA) is responsible for transmitting or expressing genetic information by directing the synthesis of thousands of proteins found in living organisms. But how do the nucleic acids perform these functions? Three processes are required: (1) replication, in which new copies of DNA are made; (2) transcription, in which a segment of DNA is used to produce RNA; and (3) translation, in which the information in RNA is translated into a protein sequence. (For more information on protein sequences, see Section 19.4 "Protein Synthesis and the Genetic Code" .) Replication New cells are continuously forming in the body through the process of cell division. For this to happen, the DNA in a dividing cell must be copied in a process known as replication The process in which the DNA in a dividing cell is copied. . The complementary base pairing of the double helix provides a ready model for how genetic replication occurs. If the two chains of the double helix are pulled apart, disrupting the hydrogen bonding between base pairs, each chain can act as a template, or pattern, for the synthesis of a new complementary DNA chain. The nucleus contains all the necessary enzymes, proteins, and nucleotides required for this synthesis. A short segment of DNA is “unzipped,” so that the two strands in the segment are separated to serve as templates for new DNA. DNA polymerase, an enzyme, recognizes each base in a template strand and matches it to the complementary base in a free nucleotide. The enzyme then catalyzes the formation of an ester bond between the 5′ phosphate group of the nucleotide and the 3′ OH end of the new, growing DNA chain. In this way, each strand of the original DNA molecule is used to produce a duplicate of its former partner ( Figure 19.9 "A Schematic Diagram of DNA Replication" ). Whatever information was encoded in the original DNA double helix is now contained in each replicate helix. When the cell divides, each daughter cell gets one of these replicates and thus all of the information that was originally possessed by the parent cell. Figure 19.9 A Schematic Diagram of DNA Replication DNA replication occurs by the sequential unzipping of segments of the double helix. Each new nucleotide is brought into position by DNA polymerase and is added to the growing strand by the formation of a phosphate ester bond. Thus, two double helixes form from one, and each consists of one old strand and one new strand, an outcome called semiconservative replications. (This representation is simplified; many more proteins are involved in replication.) Example 1 A segment of one strand from a DNA molecule has the sequence 5′‑TCCATGAGTTGA‑3′. What is the sequence of nucleotides in the opposite, or complementary, DNA chain? Solution Knowing that the two strands are antiparallel and that T base pairs with A, while C base pairs with G, the sequence of the complementary strand will be 3′‑AGGTACTCAACT‑5′ (can also be written as TCAACTCATGGA). Skill-Building Exercise A segment of one strand from a DNA molecule has the sequence 5′‑CCAGTGAATTGCCTAT‑3′. What is the sequence of nucleotides in the opposite, or complementary, DNA chain? What do we mean when we say information is encoded in the DNA molecule? An organism’s DNA can be compared to a book containing directions for assembling a model airplane or for knitting a sweater. Letters of the alphabet are arranged into words, and these words direct the individual to perform certain operations with specific materials. If all the directions are followed correctly, a model airplane or sweater is produced. In DNA, the particular sequences of nucleotides along the chains encode the directions for building an organism. Just as saw means one thing in English and was means another, the sequence of bases CGT means one thing, and TGC means something different. Although there are only four letters—the four nucleotides—in the genetic code of DNA, their sequencing along the DNA strands can vary so widely that information storage is essentially unlimited. Transcription For the hereditary information in DNA to be useful, it must be “expressed,” that is, used to direct the growth and functioning of an organism. The first step in the processes that constitute DNA expression is the synthesis of RNA, by a template mechanism that is in many ways analogous to DNA replication. Because the RNA that is synthesized is a complementary copy of information contained in DNA, RNA synthesis is referred to as transcription The process in which RNA is synthesized from a DNA template. . There are three key differences between replication and transcription: (1) RNA molecules are much shorter than DNA molecules; only a portion of one DNA strand is copied or transcribed to make an RNA molecule. (2) RNA is built from ribonucleotides rather than deoxyribonucleotides. (3) The newly synthesized RNA strand does not remain associated with the DNA sequence it was transcribed from. The DNA sequence that is transcribed to make RNA is called the template strand, while the complementary sequence on the other DNA strand is called the coding or informational strand. To initiate RNA synthesis, the two DNA strands unwind at specific sites along the DNA molecule. Ribonucleotides are attracted to the uncoiling region of the DNA molecule, beginning at the 3′ end of the template strand, according to the rules of base pairing. Thymine in DNA calls for adenine in RNA, cytosine specifies guanine, guanine calls for cytosine, and adenine requires uracil. RNA polymerase—an enzyme—binds the complementary ribonucleotide and catalyzes the formation of the ester linkage between ribonucleotides, a reaction very similar to that catalyzed by DNA polymerase ( Figure 19.10 "A Schematic Diagram of RNA Transcription from a DNA Template" ). Synthesis of the RNA strand takes place in the 5′ to 3′ direction, antiparallel to the template strand. Only a short segment of the RNA molecule is hydrogen-bonded to the template strand at any time during transcription. When transcription is completed, the RNA is released, and the DNA helix reforms. The nucleotide sequence of the RNA strand formed during transcription is identical to that of the corresponding coding strand of the DNA, except that U replaces T. Figure 19.10 A Schematic Diagram of RNA Transcription from a DNA Template The representation of RNA polymerase is proportionately much smaller than the actual molecule, which encompasses about 50 nucleotides at a time. Example 2 A portion of the template strand of a gene has the sequence 5′‑TCCATGAGTTGA‑3′. What is the sequence of nucleotides in the RNA that is formed from this template? Solution Four things must be remembered in answering this question: (1) the DNA strand and the RNA strand being synthesized are antiparallel; (2) RNA is synthesized in a 5′ to 3′ direction, so transcription begins at the 3′ end of the template strand; (3) ribonucleotides are used in place of deoxyribonucleotides; and (4) thymine (T) base pairs with adenine (A), A base pairs with uracil (U; in RNA), and cytosine (C) base pairs with guanine (G). The sequence is determined to be 3′‑AGGUACUCAACU‑5′ (can also be written as 5′‑UCAACUCAUGGA‑3′). Skill-Building Exercise A portion of the template strand of a gene has the sequence 5′‑CCAGTGAATTGCCTAT‑3′. What is the sequence of nucleotides in the RNA that is formed from this template? Three types of RNA are formed during transcription: messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA). These three types of RNA differ in function, size, and percentage of the total cell RNA ( Table 19.2 "Properties of Cellular RNA in " ). mRNA makes up only a small percent of the total amount of RNA within the cell, primarily because each molecule of mRNA exists for a relatively short time; it is continuously being degraded and resynthesized. The molecular dimensions of the mRNA molecule vary according to the amount of genetic information a given molecule contains. After transcription, which takes place in the nucleus, the mRNA passes into the cytoplasm, carrying the genetic message from DNA to the ribosomes, the sites of protein synthesis. In Section 19.5 "Mutations and Genetic Diseases", we shall see how mRNA directly determines the sequence of amino acids during protein synthesis. Table 19.2 Properties of Cellular RNA in Escherichia coli Type Function Approximate Number of Nucleotides Percentage of Total Cell RNA mRNA codes for proteins 100–6,000 ~3 rRNA component of ribosomes 120–2900 83 tRNA adapter molecule that brings the amino acid to the ribosome 75–90 14 Ribosomes A cellular substructure where proteins are synthesized. are cellular substructures where proteins are synthesized. They contain about 65% rRNA and 35% protein, held together by numerous noncovalent interactions, such as hydrogen bonding, in an overall structure consisting of two globular particles of unequal size. Molecules of tRNA, which bring amino acids (one at a time) to the ribosomes for the construction of proteins, differ from one another in the kinds of amino acid each is specifically designed to carry. A set of three nucleotides, known as a codon A set of three nucleotides on the mRNA that specifies a particular amino acid. , on the mRNA determines which kind of tRNA will add its amino acid to the growing chain. (For more information on sequences, see Section 19.4 "Protein Synthesis and the Genetic Code" .) Each of the 20 amino acids found in proteins has at least one corresponding kind of tRNA, and most amino acids have more than one. The two-dimensional structure of a tRNA molecule has three distinctive loops, reminiscent of a cloverleaf ( Figure 19.11 "Transfer RNA" ). On one loop is a sequence of three nucleotides that varies for each kind of tRNA. This triplet, called the anticodon A set of three nucleotides on the tRNA that is complementary to, and pairs with, the codon on the mRNA. , is complementary to and pairs with the codon on the mRNA. At the opposite end of the molecule is the acceptor stem, where the amino acid is attached. Figure 19.11 Transfer RNA (a) In the two-dimensional structure of a yeast tRNA molecule for phenylalanine, the amino acid binds to the acceptor stem located at the 3′ end of the tRNA primary sequence. (The nucleotides that are not specifically identified here are slightly altered analogs of the four common ribonucleotides A, U, C, and G.) (b) In the three-dimensional structure of yeast phenylalanine tRNA, note that the anticodon loop is at the bottom and the acceptor stem is at the top right. (c) This shows a space-filling model of the tRNA. Answers Each strand of the parent DNA double helix remains associated with the newly synthesized DNA strand. DNA serves as a template for the synthesis of an RNA strand (the product of transcription). codon: mRNA; anticodon: tRNA Key Takeaways In DNA replication, each strand of the original DNA serves as a template for the synthesis of a complementary strand. DNA polymerase is the primary enzyme needed for replication. In transcription, a segment of DNA serves as a template for the synthesis of an RNA sequence. RNA polymerase is the primary enzyme needed for transcription. Three types of RNA are formed during transcription: mRNA, rRNA, and tRNA. Exercises Describe how replication and transcription are similar. Describe how replication and transcription differ. A portion of the coding strand for a given gene has the sequence 5′‑ATGAGCGACTTTGCGGGATTA‑3′. What is the sequence of complementary template strand? What is the sequence of the mRNA that would be produced during transcription from this segment of DNA? A portion of the coding strand for a given gene has the sequence 5′‑ATGGCAATCCTCAAACGCTGT‑3′. What is the sequence of complementary template strand? What is the sequence of the mRNA that would be produced during transcription from this segment of DNA? Answers Both processes require a template from which a complementary strand is synthesized. 3′‑TACTCGCTGAAACGCCCTAAT‑5′ 5′‑AUGAGCGACUUUGCGGGAUUA‑3′	msmarco_doc_00_12030099
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s23-01-atp-the-universal-energy-curre.html	ATP—the Universal Energy Currency	20.1 ATP—the Universal Energy Currency 20.1 ATP—the Universal Energy Currency Learning Objective Note Answer Key Takeaway Exercises Answers	ATP—the Universal Energy Currency 20.1 ATP—the Universal Energy Currency Learning Objective Describe the importance of ATP as a source of energy in living organisms. Adenosine triphosphate (ATP), a nucleotide composed of adenine, ribose, and three phosphate groups, is perhaps the most important of the so-called energy-rich compounds in a cell. Its concentration in the cell varies from 0.5 to 2.5 mg/mL of cell fluid. Energy-rich compounds are substances having particular structural features that lead to a release of energy after hydrolysis. As a result, these compounds are able to supply energy for biochemical processes that require energy. The structural feature important in ATP is the phosphoric acid anhydride, or pyrophosphate, linkage: The pyrophosphate bond, symbolized by a squiggle (~), is hydrolyzed when ATP is converted to adenosine diphosphate (ADP). In this hydrolysis reaction, the products contain less energy than the reactants; there is a release of energy (> 7 kcal/mol). One reason for the amount of energy released is that hydrolysis relieves the electron-electron repulsions experienced by the negatively charged phosphate groups when they are bonded to each other ( Figure 20.3 "Hydrolysis of ATP to Form ADP" ). Figure 20.3 Hydrolysis of ATP to Form ADP Energy is released because the products (ADP and phosphate ion) have less energy than the reactants [ATP and water (H 2 O)]. The general equation for ATP hydrolysis is as follows: ATP + H2O → ADP + Pi + 7.4 kcal/mol If the hydrolysis of ATP releases energy, its synthesis (from ADP) requires energy. In the cell, ATP is produced by those processes that supply energy to the organism (absorption of radiant energy from the sun in green plants and breakdown of food in animals), and it is hydrolyzed by those processes that require energy (the syntheses of carbohydrates, lipids, proteins; the transmission of nerve impulses; muscle contractions). In fact, ATP is the principal medium of energy exchange in biological systems. Many scientists call it the energy currency of cells. Note P i is the symbol for the inorganic phosphate anions H 2 PO 4− and HPO 42−. ATP is not the only high-energy compound needed for metabolism. Several others are listed in Table 20.1 "Energy Released by Hydrolysis of Some Phosphate Compounds". Notice, however, that the energy released when ATP is hydrolyzed is approximately midway between those of the high-energy and the low-energy phosphate compounds. This means that the hydrolysis of ATP can provide energy for the phosphorylation of the compounds below it in the table. For example, the hydrolysis of ATP provides sufficient energy for the phosphorylation of glucose to form glucose 1-phosphate. By the same token, the hydrolysis of compounds, such as creatine phosphate, that appear above ATP in the table can provide the energy needed to resynthesize ATP from ADP. Table 20.1 Energy Released by Hydrolysis of Some Phosphate Compounds Type Example Energy Released (kcal/mol) acyl phosphate 1,3-bisphosphoglycerate (BPG) −11.8 acetyl phosphate −11.3 guanidine phosphates creatine phosphate −10.3 arginine phosphate −9.1 pyrophosphates PP i* → 2P i −7.8 ATP → AMP + PP i −7.7 ATP → ADP + P i −7.5 ADP → AMP + P i −7.5 sugar phosphates glucose 1-phosphate −5.0 fructose 6-phosphate −3.8 AMP → adenosine + P i −3.4 glucose 6-phosphate −3.3 glycerol 3-phosphate −2.2 *PPi is the pyrophosphate ion. Answer ATP is the principal molecule involved in energy exchange reactions in biological systems. Key Takeaway The hydrolysis of ATP releases energy that can be used for cellular processes that require energy. Exercises How do ATP and ADP differ in structure? Why does the hydrolysis of ATP to ADP involve the release of energy? Identify whether each compound would be classified as a high-energy phosphate compound. ATP glucose 6-phosphate creatine phosphate Identify whether each compound would be classified as a high-energy phosphate compound. ADP AMP glucose 1-phosphate Answers ATP has a triphosphate group attached, while ADP has only a diphosphate group attached. yes no yes	msmarco_doc_00_12043511
http://2012books.lardbucket.org/books/introduction-to-chemistry-general-organic-and-biological/s23-02-stage-i-of-catabolism.html	Stage I of Catabolism	20.2 Stage I of Catabolism 20.2 Stage I of Catabolism Learning Objective Digestion of Carbohydrates Digestion of Proteins Note Digestion of Lipids Answers Key Takeaways Exercises Answers	Stage I of Catabolism 20.2 Stage I of Catabolism Learning Objective Describe how carbohydrates, fats, and proteins are broken down during digestion. We have said that animals obtain chemical energy from the food—carbohydrates, fats, and proteins—they eat through reactions defined collectively as catabolism. We can think of catabolism as occurring in three stages ( Figure 20.4 "Energy Conversions" ). In stage I, carbohydrates, fats, and proteins are broken down into their individual monomer units: carbohydrates into simple sugars, fats into fatty acids and glycerol, and proteins into amino acids. One part of stage I of catabolism is the breakdown of food molecules by hydrolysis reactions into the individual monomer units—which occurs in the mouth, stomach, and small intestine—and is referred to as digestion The breakdown of food molecules by hydrolysis reactions into the individual monomer units in the mouth, stomach, and small intestine. . In stage II, these monomer units (or building blocks) are further broken down through different reaction pathways, one of which produces ATP, to form a common end product that can then be used in stage III to produce even more ATP. In this chapter, we will look at each stage of catabolism—as an overview and in detail. Figure 20.4 Energy Conversions The conversion of food into cellular energy (as ATP) occurs in three stages. Digestion of Carbohydrates Carbohydrate digestion begins in the mouth ( Figure 20.5 "The Principal Events and Sites of Carbohydrate Digestion" ), where salivary α-amylase attacks the α-glycosidic linkages in starch, the main carbohydrate ingested by humans. Cleavage of the glycosidic linkages produces a mixture of dextrins, maltose, and glucose. (For more information about carbohydrates, see Chapter 16 "Carbohydrates" .) The α-amylase mixed into the food remains active as the food passes through the esophagus, but it is rapidly inactivated in the acidic environment of the stomach. Figure 20.5 The Principal Events and Sites of Carbohydrate Digestion The primary site of carbohydrate digestion is the small intestine. The secretion of α-amylase in the small intestine converts any remaining starch molecules, as well as the dextrins, to maltose. Maltose is then cleaved into two glucose molecules by maltase. Disaccharides such as sucrose and lactose are not digested until they reach the small intestine, where they are acted on by sucrase and lactase, respectively. The major products of the complete hydrolysis of disaccharides and polysaccharides are three monosaccharide units: glucose, fructose, and galactose. These are absorbed through the wall of the small intestine into the bloodstream. Digestion of Proteins Protein digestion begins in the stomach ( Figure 20.6 "The Principal Events and Sites of Protein Digestion" ), where the action of gastric juice hydrolyzes about 10% of the peptide bonds. Gastric juice A mixture of water, inorganic ions, hydrochloric acid, and various enzymes and proteins found in the stomach. is a mixture of water (more than 99%), inorganic ions, hydrochloric acid, and various enzymes and other proteins. Note The pain of a gastric ulcer is at least partially due to irritation of the ulcerated tissue by acidic gastric juice. Figure 20.6 The Principal Events and Sites of Protein Digestion The hydrochloric acid (HCl) in gastric juice is secreted by glands in the stomach lining. The pH of freshly secreted gastric juice is about 1.0, but the contents of the stomach may raise the pH to between 1.5 and 2.5. HCl helps to denature food proteins; that is, it unfolds the protein molecules to expose their chains to more efficient enzyme action. The principal digestive component of gastric juice is pepsinogen, an inactive enzyme produced in cells located in the stomach wall. When food enters the stomach after a period of fasting, pepsinogen is converted to its active form—pepsin—in a series of steps initiated by the drop in pH. Pepsin catalyzes the hydrolysis of peptide linkages within protein molecules. It has a fairly broad specificity but acts preferentially on linkages involving the aromatic amino acids tryptophan, tyrosine, and phenylalanine, as well as methionine and leucine. Protein digestion is completed in the small intestine. Pancreatic juice, carried from the pancreas via the pancreatic duct, contains inactive enzymes such as trypsinogen and chymotrypsinogen. They are activated in the small intestine as follows ( Figure 20.7 "Activation of Some Pancreatic Enzymes in the Small Intestine" ): The intestinal mucosal cells secrete the proteolytic enzyme enteropeptidase, which converts trypsinogen to trypsin; trypsin then activates chymotrypsinogen to chymotrypsin (and also completes the activation of trypsinogen). Both of these active enzymes catalyze the hydrolysis of peptide bonds in protein chains. Chymotrypsin preferentially attacks peptide bonds involving the carboxyl groups of the aromatic amino acids (phenylalanine, tryptophan, and tyrosine). Trypsin attacks peptide bonds involving the carboxyl groups of the basic amino acids (lysine and arginine). Pancreatic juice also contains procarboxypeptidase, which is cleaved by trypsin to carboxypeptidase. The latter is an enzyme that catalyzes the hydrolysis of peptide linkages at the free carboxyl end of the peptide chain, resulting in the stepwise liberation of free amino acids from the carboxyl end of the polypeptide. Figure 20.7 Activation of Some Pancreatic Enzymes in the Small Intestine Aminopeptidases in the intestinal juice remove amino acids from the N-terminal end of peptides and proteins possessing a free amino group. Figure 20.8 "Hydrolysis of a Peptide by Several Peptidases" illustrates the specificity of these protein-digesting enzymes. The amino acids that are released by protein digestion are absorbed across the intestinal wall into the circulatory system, where they can be used for protein synthesis. Figure 20.8 Hydrolysis of a Peptide by Several Peptidases This diagram illustrates where in a peptide the different peptidases we have discussed would catalyze hydrolysis the peptide bonds. Digestion of Lipids Lipid digestion begins in the upper portion of the small intestine ( Figure 20.9 "The Principal Events and Sites of Lipid (Primarily Triglyceride) Digestion" ). A hormone secreted in this region stimulates the gallbladder to discharge bile into the duodenum. The principal constituents of bile are the bile salts, which emulsify large, water-insoluble lipid droplets, disrupting some of the hydrophobic interactions holding the lipid molecules together and suspending the resulting smaller globules (micelles) in the aqueous digestive medium. (For more information on bile salts, see Chapter 17 "Lipids", Section 17.4 "Steroids" .) These changes greatly increase the surface area of the lipid particles, allowing for more intimate contact with the lipases and thus rapid digestion of the fats. Another hormone promotes the secretion of pancreatic juice, which contains these enzymes. Figure 20.9 The Principal Events and Sites of Lipid (Primarily Triglyceride) Digestion The lipases in pancreatic juice catalyze the digestion of triglycerides first to diglycerides and then to 2‑monoglycerides and fatty acids: The monoglycerides and fatty acids cross the intestinal lining into the bloodstream, where they are resynthesized into triglycerides and transported as lipoprotein complexes known as chylomicrons. Phospholipids and cholesteryl esters undergo similar hydrolysis in the small intestine, and their component molecules are also absorbed through the intestinal lining. The further metabolism of monosaccharides, fatty acids, and amino acids released in stage I of catabolism occurs in stages II and III of catabolism. Answers Pepsinogen is an inactive form of pepsin; pepsin is the active form of the enzyme. Both enzymes catalyze the hydrolysis of peptide bonds. Chymotrypsin catalyzes the hydrolysis of peptide bonds following aromatic amino acids, while trypsin catalyzes the hydrolysis of peptide bonds following lysine and arginine. Aminopeptidase catalyzes the hydrolysis of amino acids from the N-terminal end of a protein, while carboxypeptidase catalyzes the hydrolysis of amino acids from the C-terminal end of a protein. glucose, fructose, and galactose monoglycerides and fatty acids amino acids the small intestine Key Takeaways During digestion, carbohydrates are broken down into monosaccharides, proteins are broken down into amino acids, and triglycerides are broken down into glycerol and fatty acids. Most of the digestion reactions occur in the small intestine. Exercises What are the products of digestion (or stage I of catabolism)? What is the general type of reaction used in digestion? Give the site of action and the function of each enzyme. chymotrypsin lactase pepsin maltase Give the site of action and the function of each enzyme. α-amylase trypsin sucrase aminopeptidase What is the meaning of the following statement? “Bile salts act to emulsify lipids in the small intestine.” Why is emulsification important? Using chemical equations, describe the chemical changes that triglycerides undergo during digestion. What are the expected products from the enzymatic action of chymotrypsin on each amino acid segment? gly-ala-phe-thr-leu ala-ile-tyr-ser-arg val-trp-arg-leu-cys What are the expected products from the enzymatic action of trypsin on each amino acid segment? leu-thr-glu-lys-ala phe-arg-ala-leu-val ala-arg-glu-trp-lys Answers proteins: amino acids; carbohydrates: monosaccharides; fats: fatty acids and glycerol Chymotrypsin is found in the small intestine and catalyzes the hydrolysis of peptide bonds following aromatic amino acids. Lactase is found in the small intestine and catalyzes the hydrolysis of lactose. Pepsin is found in the stomach and catalyzes the hydrolysis of peptide bonds, primarily those that occur after aromatic amino acids. Maltase is found in the small intestine and catalyzes the hydrolysis of maltose. Bile salts aid in digestion by dispersing lipids throughout the aqueous solution in the small intestine. Emulsification is important because lipids are not soluble in water; it breaks lipids up into smaller particles that can be more readily hydrolyzed by lipases. gly-ala-phe and thr-leu ala-ile-tyr and ser-arg val-trp and arg-leu-cys	msmarco_doc_00_12048224
http://2012books.lardbucket.org/books/introduction-to-criminal-law/s06-02-the-branches-of-government.html	The Branches of Government	2.2 The Branches of Government 2.2 The Branches of Government Learning Objectives The Legislative Branch Examples of Legislative Branch Checks and Balances The Executive Branch Examples of Executive Branch Checks and Balances The Judicial Branch Examples of Judicial Branch Checks and Balances Key Takeaways Exercises	The Branches of Government 2.2 The Branches of Government Learning Objectives Identify the three branches of government. Ascertain the head of the federal and state legislative branches of government. Compare the Senate and the House of Representatives. Ascertain the head of the federal and state executive branches of government. Ascertain the head of the federal and state judicial branches of government. The federal Constitution was written to ensure that government power is distributed and never concentrated in one or more areas. This philosophy is served by federalism, where the federal government shares power with the states. It is also further served by dividing the government into three branches, all responsible for different government duties and all checking and balancing each other. The three branches of government are detailed in Articles I–III of the federal Constitution and are the legislative branch The branch of government responsible for creating statutory law. , the executive branch The branch of government responsible for enforcing statutory law. , and the judicial branch The branch of government responsible for interpreting statutory and constitutional law (s). . While the federal Constitution identifies only the federal branches of government, the principle of checks and balances applies to the states as well. Most states identify the three state branches of government in their state constitution. Each branch of government has a distinct authority. When one branch encroaches on the duties of another, this is called a violation of separation of powers Each government branch must act only within the scope set forth in the Constitution. . The courts decide whether a government branch has overstepped its boundaries because courts interpret the Constitution, which describes each branch’s sphere of influence. Thus the judicial branch, which consists of all the courts, retains the balance of power. The Legislative Branch The legislative branch is responsible for creating statutory laws. Citizens of a state can vote for some state statutes by ballot, but the federal legislative branch enacts all federal statutes. In the federal government, the legislative branch is headed by Congress. States’ legislative branches are headed by a state legislature. Congress is bicameral Made up of two houses. , which means it is made up of two houses. This system provides equal representation among the several states and by citizens of the United States. States are represented by the Senate The house of Congress responsible for representing each state. . Every state, no matter how large or small, gets two senators. Citizens are represented by the House of Representatives The house of Congress responsible for representing each citizen of the United States. . Membership in the House of Representatives is based on population. A heavily populated state, like California, has more representatives than a sparsely populated state, like Alaska. States’ legislatures are generally bicameral and have a similar structure to the federal system. Figure 2.4 Diagram of the Legislative Branch Examples of Legislative Branch Checks and Balances The legislative branch can check and balance both the executive branch and the judicial branch. Congress can impeach the president of the United States, which is the first step toward removal from office. Congress can also enact statutes that supersede judicial opinions, as discussed in Chapter 1 "Introduction to Criminal Law". Similarly, state legislature can also impeach a governor or enact a state statute that supersedes a state case law. The Executive Branch The executive branch is responsible for enforcing the statutes enacted by the legislative branch. In the federal government, the executive branch is headed by the president of the United States. States’ executive branches are headed by the governor of the state. Figure 2.5 Diagram of the Executive Branch Examples of Executive Branch Checks and Balances The executive branch can check and balance both the legislative branch and the judicial branch. The president of the United States can veto statutes proposed by Congress. The president also has the authority to nominate federal justices and judges, who thereafter serve for life. State executive branches have similar check and balancing authority; a governor can generally veto statutes proposed by state legislature and can appoint some state justices and judges. The Judicial Branch The judicial branch is responsible for interpreting all laws, including statutes, codes, ordinances, and the federal and state constitutions. This power is all encompassing and is the basis for judicial review, referenced in Chapter 1 "Introduction to Criminal Law". It allows the judicial branch to invalidate any unconstitutional law in the statutory source of law and also to change the federal and state constitutions by interpretation. For example, when a court creates an exception to an amendment to the constitution, it has made an informal change without the necessity of a national or state consensus. The federal judicial branch is headed by the US Supreme Court. Each state’s judicial branch is headed by the highest-level state appellate court. Members of the judicial branch include all judges and justices of every federal and state court in the court system, which is discussed shortly. Figure 2.6 Diagram of the Judicial Branch Examples of Judicial Branch Checks and Balances The judicial branch can check and balance both the legislative branch and the executive branch. The US Supreme Court can invalidate statutes enacted by Congress if they conflict with the Constitution. The US Supreme Court can also prevent the president from taking action if that action violates separation of powers. The state courts can likewise nullify unconstitutional statutes passed by the state legislature and void other executive branch actions that are unconstitutional. Table 2.1 The Most Prominent Checks and Balances between the Branches Government Branch Duty or Authority Check and Balance Government Branch Checking and Balancing Legislative Create statutes President can veto Executive Executive Enforce statutes Congress can override presidential veto by 2/3 majority Legislative Judicial Interpret statutes and Constitution President nominates federal judges and justices Executive Executive Enforce statutes Senate can confirm or reject presidential nomination of federal judges and justices Legislative Executive Enforce statutes Congress can impeach the president Legislative Legislative Create statutes Courts can invalidate unconstitutional statutes Judicial Executive Enforce statutes Courts can invalidate unconstitutional executive action Judicial Judicial Interpret statutes and Constitution Statutes can supersede case law Legislative Key Takeaways The three branches of government are the legislative branch, the executive branch, and the judicial branch. The head of the federal legislative branch of government is Congress. The head of the state legislative branch of government is the state legislature. The Senate represents every state equally because each state has two senators. The House of Representatives represents each citizen equally because states are assigned representatives based on their population. The head of the federal executive branch of government is the president. The head of each state executive branch of government is the governor. The head of the federal judicial branch of government is the US Supreme Court. The head of each state judicial branch of government is the highest-level state appellate court. Exercises Answer the following questions. Check your answers using the answer key at the end of the chapter. A mayor enacts a policy that prohibits police officers in his city from enforcing a state law prohibiting the possession and use of marijuana. The mayor’s policy specifically states that within the city limits, marijuana is legal to possess and use. Which constitutional principle is the mayor violating? Which branch of government should check and balance the mayor’s behavior in this matter? Read Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579 (1952). In Youngstown, President Truman seized control of steel mills to avert a strike, using his authority as commander in chief of the armed forces. President Truman wanted to ensure steel production during the Korean War. Did the US Supreme Court uphold President Truman’s action? Why or why not? The case is available at this link: http://supreme.justia.com/us/343/579/. Read Hamdi v. Rumsfeld, 542 U.S. 507 (2004). In Hamdi, the US Supreme Court reviewed the US Court of Appeals for the Fourth Circuit’s decision prohibiting the release of a US citizen who was held as an enemy combatant in Virginia during the Afghanistan War. The citizen’s detention was based on a federal statute that deprived him of the opportunity to consult with an attorney or have a trial. Did the US Supreme Court defer to the federal statute? Why or why not? The case is available at this link: http://scholar.google.com/scholar_case?case=6173897153146757813&hl=en&as_sdt=2&as_vis=1&oi=scholarr.	msmarco_doc_00_12059204
http://2012books.lardbucket.org/books/introduction-to-criminal-law/s17-03-perjury-bribery-and-obstructio.html	Perjury, Bribery, and Obstruction of Justice	13.3 Perjury, Bribery, and Obstruction of Justice 13.3 Perjury, Bribery, and Obstruction of Justice Learning Objectives Perjury History and Elements Necessity of a Valid Oath Perjury Criminal Intent Materiality Requirement Corroborative Evidence Requirement Defense of Retraction Example of a Case Lacking an Element of Perjury Example of Perjury Perjury by Inconsistent Statements Example of Perjury by Inconsistent Statements Subornation of Perjury Example of a Case Lacking an Element of Subornation of Perjury Perjury Grading Bribery Elements Prosecutorial Burden in Bribery Prosecutions Example of Bribery Another Example of Bribery Example of a Case Lacking an Element of Bribery Bribery When No Authority to Act Is Present Example of Bribery When No Authority to Act Is Present Bribery Grading Obstruction of Justice Example of Obstruction of Justice The Barry Bonds Verdict Video Additional Crimes against the Government Key Takeaways Exercises Law and Ethics Clinton Declaration and Admission Videos	Perjury, Bribery, and Obstruction of Justice 13.3 Perjury, Bribery, and Obstruction of Justice Learning Objectives Define the elements of perjury. Identify the issues commonly encountered in a perjury prosecution. Identify a potential defense to perjury. Define perjury by inconsistent statements and subornation of perjury. Analyze perjury and subornation of perjury grading. Define the elements of bribery, identify the primary difficulty in a prosecution for this offense, and analyze bribery grading. Define the elements of various forms of obstruction of justice, and analyze obstruction of justice grading. Crimes against the administration of justice impede the government’s ability to carry out the important functions of prosecuting and convicting criminals, which, in turn, destroys citizens’ confidence that the US legal system is effective in ensuring individual safety and security. This section analyzes perjury, bribery, and obstruction of justice, along with the issues commonly encountered when prosecuting these offenses. Additional statutes criminalizing contempt of court, resisting arrest, and escape are also available for review. Perjury History and Elements Witness testimony is important in a variety of settings. Juries depend on witness testimony to reach a fair and impartial verdict in civil and criminal trials, and grand juries depend on witness testimony to indict defendants for criminal conduct. Thus modern laws of perjury A false material statement made under oath in a judicial or official proceeding or in a certified writing with awareness of the falsity of the statement or the specific intent to deceive. are calculated to ensure that witnesses testify truthfully so that justice can be done in each individual case. In the Middle Ages, the witnesses were the jurors, so the criminalization of false witness testimony did not occur until the sixteenth century when the idea of a trial by an impartial jury emerged. The first common-law prohibition against witness perjury criminalized false testimony, given under oath, in a judicial proceeding, about a material issue. This definition was also incorporated into early American common law. “Perjury—Perjury at Common Law,” Jrank.org website, accessed May 5, 2011, http://law.jrank.org/pages/1632/Perjury-Perjury-at-common-law.html. In modern times, every state prohibits perjury, as well as the federal government. 18 U.S.C. § 1621, accessed May 5, 2011, http://www.law.cornell.edu/uscode/718/usc_sec_18_00001621----000-.html. Most state statutes or state common law, in states that allow common-law crimes, define perjury as a false material statement ( criminal act ), made with the specific intent or purposely to deceive, or the general intent or knowingly that the statement was false, in a judicial or official proceeding ( attendant circumstance ), under oath ( attendant circumstance ). Ga. Code tit. 16 § 16-10-70, accessed May 5, 2011, http://law.onecle.com/georgia/16/16-10-70.html. The Model Penal Code defines perjury as a false material statement, that the defendant does not believe to be true, made under oath in any official proceeding (Model Penal Code § 241.1 (1)). The biggest issues commonly encountered in any perjury prosecution are proving the validity of the oath, the defendant’s criminal intent, the materiality of the false statement, and any requirement of corroborative evidence. Necessity of a Valid Oath The defendant must be under oath when making the statement at issue in any perjury prosecution, and the oath must be administered by someone of legal authority or someone authorized to take evidence under oath, Connecticut Jury Instructions § 53a-156, accessed May 5, 2011, http://www.jud.ct.gov/ji/criminal/part4/4.5-9.htm. including a referee, hearing examiner, commissioner, notary, or other person authorized to take evidence in connection with an official or judicial proceeding. Connecticut Jury Instructions § 53a-156, accessed May 5, 2011, http://www.jud.ct.gov/ji/criminal/part4/4.5-9.htm. Federally and in many jurisdictions, the false statement can be written, as long as it is certified, such as a signature on an income tax return 18 U.S.C. § 6065, accessed May 5, 2011, http://www.law.cornell.edu/uscode/26/usc_sec_26_00006065----000-.html. or a report. Cal. Penal Code § 129, accessed May 5, 2011, http://law.onecle.com/california/penal/129.html. The Model Penal Code also considers a false written statement perjury, as long as the document containing the statement is made upon oath or affirmation (Model Penal Code § 241.1 (3)). In spite of the attendant circumstance requirement that the statement be made under oath, many jurisdictions disallow a defense to a prosecution for perjury based on the assertion that the oath or affirmation was administered or taken in an irregular manner. Ala. Code § 13A-10-108, accessed May 5, 2011, http://law.onecle.com/alabama/criminal-code/13A-10-108.html. The Model Penal Code has a similar provision (Model Penal Code § 241.1 (3)). In addition, many jurisdictions have a provision that witnesses who refuse to take an oath shall have the option of making a nonreligous affirmation that has the same legal effect as the oath. 42 Pa. Cons. Stat. Ann. § 5901, accessed May 5, 2011, http://law.onecle.com/pennsylvania/judiciary-and-judicial-procedure/00.059.001.000.html. The Model Penal Code allows for an “oath or equivalent affirmation” (Model Penal Code § 241.1 (1)). Perjury Criminal Intent As stated previously, in many jurisdictions, the defendant must know that a statement is false or must make the statement with the specific intent or purposely to deceive. When the intent requirement is general intent or knowledge that the statement is false, proof that the statement is false could give rise to an inference of intent. State v. Kimber, 48 Conn. App. 234 (1998), accessed May 5, 2011, http://scholar.google.com/scholar_case?case=17399056576949304157&q= State+v.+Kimber+48&hl=en&as_sdt=2,5. Materiality Requirement Perjury generally requires a false statement that is material, which means that it substantially affected or could substantially affect the outcome of the proceeding. Mo. Ann. Stat. § 575.040, accessed May 5, 2011, http://www1.law.umkc.edu/suni/CrimLaw/calendar/Class_4_Mo_perjury.htm. In many jurisdictions and federally, materiality is a question of fact for the trier of fact, which could be a jury. U.S. v. Gaudin, 515 U.S. 506 (1995), accessed May 5, 2011, http://scholar.google.com/scholar_case?case=12281686524757008977&hl=en&as_sdt=2&as_vis=1&oi=scholarr. The Model Penal Code defines materiality as a statement that could have affected the course or outcome of the proceeding and declares that materiality should be a question of law, which means it should be determined by a judge, not a jury (Model Penal Code § 241.1 (2)). Typically, it is not a defense to perjury that the defendant did not know that the statement was material. Mo. Ann. Stat. § 575.040 (3) (1), accessed May 5, 2011, http://www1.law.umkc.edu/suni/CrimLaw/calendar/Class_4_Mo_perjury.htm. The Model Penal Code has a similar provision (Model Penal Code § 241.1 (2)). Corroborative Evidence Requirement Some jurisdictions have a requirement of corroborative evidence for perjury, which necessitates the testimony of two witnesses to support a conviction, similar to a treason conviction. Tex. Code of Criminal Procedure, § 38.18, accessed May 5, 2011, http://law.onecle.com/texas/criminal-procedure/38.18.00.html. The Model Penal Code also has this corroborative evidence requirement (Model Penal Code § 241.1 (6)). Defense of Retraction Many jurisdictions provide a defense to perjury if the defendant retracts his or her false statement in the course of the same proceeding in which it was made before it becomes manifest that the falsification will be exposed. Ala. Code § 13A-10-107, accessed May 6, 2011, http://law.onecle.com/alabama/criminal-code/13A-10-107.html. The Model Penal Code has a similar provision (Model Penal Code § 241.1 (4)). Example of a Case Lacking an Element of Perjury Marcus is a witness in a civil suit for damages against Lindsay. Macy’s department store is suing Lindsay for the alleged theft of a diamond necklace. Marcus takes an oath sworn by the court commissioner. He thereafter testifies that he saw Lindsay try on the necklace and then walk out of the store without paying for it. When the Macy’s attorney asks Marcus what he was doing at Macy’s, Marcus responds that he was buying some jewelry as a gift for his wife. In actuality, Marcus was shopping for jewelry as a gift for his girlfriend. Marcus has probably not committed perjury in this case. Marcus is testifying as a witness in a civil rather than criminal trial, but this satisfies the perjury requirement that the testimony be offered during a judicial or official proceeding. Before testifying, Marcus took an oath that was administered by a court commissioner, also satisfying the perjury requirement that the defendant take an oath administered by someone with the legal authority or authorization to take evidence under oath. Marcus’s statement is false, and he made the statement with knowledge of its falsity, which satisfies the perjury criminal intent requirement. However, Marcus’s statement does not appear to be material to this judicial proceeding because the reason for Marcus’s presence at Macy’s will not affect the outcome of Lindsay’s civil theft trial (usually called the tort of conversion). Thus Marcus is probably not subject to prosecution for and conviction of perjury, based on his testimony in this case. Example of Perjury Review the example in Section 13 "Example of a Case Lacking an Element of Perjury" with Marcus. Change this example so that Marcus testifies that he did not see Lindsay walk out of the Macy’s department store without paying for the necklace because he does not want to admit that he was shopping for jewelry to buy his girlfriend. Anthony, the Macy’s civil trial attorney, cross-examines Marcus, and forces him to admit that he saw Lindsay steal the necklace, and that he was lying previously. Marcus has most likely committed perjury in this example. Marcus made a false statement, under a validly administered oath, in a judicial proceeding, with knowledge of its falsity. Marcus’s statement was material because, if believed, it would have helped exonerate Lindsay in her civil case. In many jurisdictions, the trier of fact, which could be a judge or jury, determines whether or not the statement is material. Marcus’s admission that he was lying is not a retraction that could serve as a defense because it was not made until the lie was about to be exposed. Thus all the elements of perjury appear to be present, and Marcus may be subject to prosecution for and conviction of this offense. Figure 13.6 Diagram of Defenses to Perjury Perjury by Inconsistent Statements Some jurisdictions criminalize perjury by inconsistent or contradictory statements The defendant makes inconsistent statements under oath in a judicial or official proceeding. , which is slightly different from criminal perjury. Ala. Code § 13A-10-104, accessed May 6, 2011, http://law.onecle.com/alabama/criminal-code/13A-10-104.html. Perjury by inconsistent statements is easier to prove than traditional perjury because the prosecution can simply offer evidence that the defendant made statements that are inconsistent, in a judicial proceeding, after taking a validly administered oath. Corroborative evidence is not required, and the prosecution does not have the burden of proving that one of the statements is false, just that one or the other was false and not believed by the defendant to be true. Ala. Code § 13A-10-104, accessed May 6, 2011, http://law.onecle.com/alabama/criminal-code/13A-10-104.html. The Model Penal Code has a similar provision (Model Penal Code § 241.1 (5)). Example of Perjury by Inconsistent Statements Review the example with Marcus in Section 13 "Example of Perjury". If Marcus’s jurisdiction criminalizes perjury by inconsistent statements, Marcus could most likely be prosecuted for this offense. Marcus made two inconsistent statements while under a validly administered oath in Lindsay’s conversion trial, which is a judicial proceeding. In Marcus’s criminal perjury by inconsistent statements prosecution, the prosecutor need only offer evidence of the inconsistent statements to the trier of fact. The prosecutor does not have to provide corroborative evidence and does not have the burden of proving that the first statement was false, which will simplify and expedite the trial and may subject Marcus to conviction of this offense. Subornation of Perjury Most jurisdictions criminalize subornation of perjury Procuring another to commit perjury. , which is typically procuring another to commit perjury ( criminal act) with specific intent or purposely, or general intent or knowingly, and factually and legally causing the resulting harm that perjury is in fact committed. N.C. Gen. Stat. § 14-210, accessed May 6, 2011, http://law.onecle.com/north-carolina/14-criminal-law/14-210.html. Example of a Case Lacking an Element of Subornation of Perjury Review the example given with Marcus in Section 13 "Example of Perjury". Add to this example and assume that Marcus begs Janelle, another witness in Lindsay’s conversion trial, to say that she did not see him at Macy’s the day Lindsay stole the necklace. Janelle flatly refuses. Marcus has not committed subornation of perjury in this case. Although Marcus tried to procure Janelle to commit perjury, with specific intent or purposely, Janelle did not cooperate and did not commit the perjury. Thus the harm element of subornation of perjury is lacking, and Marcus can be prosecuted only for attempted subornation of perjury or solicitation to commit perjury, rather than the completed offense. Figure 13.7 Comparison of Perjury by Inconsistent Statements and Subornation of Perjury Perjury Grading Perjury is generally graded as a felony, N.C. Gen. Stat. § 14-209, accessed May 6, 2011, http://law.onecle.com/north-carolina/14-criminal-law/14-209.html. with a potential sentencing enhancement for committing perjury that causes another to be sentenced to prison or the death penalty. Ga. Code tit. 16, § 16-10-70, accessed May 6, 2011, http://law.onecle.com/georgia/16/16-10-70.html. The Model Penal Code grades perjury as a felony of the third degree (Model Penal Code § 241.1 (1)). Subornation of perjury is also graded as a felony. N.C. Gen. Stat. § 14-210, accessed May 6, 2011, http://law.onecle.com/north-carolina/14-criminal-law/14-210.html. However, because of the procedural difficulties in successfully convicting a defendant of perjury and subornation of perjury, these crimes are not often prosecuted. Nonetheless, the threat of a felony conviction still serves as a deterrent and helps to ensure that witnesses testify truthfully in judicial and official proceedings and give accurate statements in certified writings. Bribery Elements Bribery Offering, conferring, agreeing to confer, or soliciting, accepting, or agreeing to accept a benefit to or from a designated individual for the purpose of influencing decision making. is often compared to extortion, yet extortion is considered a crime of threatened force or violence, while bribery involves financial inducement. U.S. v. Adcock, 558 F.2d 397 (1977), accessed May 6, 2011, http://scholar.google.com/scholar_case?case=189694239263939940&hl=en&as_sdt=2&as_vis=1&oi=scholarr. At early common law, bribery was the receiving or offering any undue reward by or to any person in a public office in order to influence his or her behavior in office and induce him or her to act contrary to the known rules of honesty and integrity. Legal definition of bribery, Duhaime.org website, accessed May 6, 2011, http://www.duhaime.org/LegalDictionary/B/Bribery.aspx. In modern times, many criminal statutes define bribery as conferring, offering, agreeing to confer, or soliciting, accepting, or agreeing to accept any benefit upon a public official ( criminal act) with the specific intent or purposely or the general intent or knowingly to form an agreement or understanding that the public official’s vote, opinion, judgment, action, decision, or exercise of discretion will be influenced by the benefit. N.Y. Penal Law § 200.00, accessed May 6, 2011, http://law.onecle.com/new-york/penal/PEN0200.00_200.00.html; N.Y. Penal Law § 200.10, http://law.onecle.com/new-york/penal/PEN0200.10_200.10.html. The crime of bribery is often extended to apply to persons other than public officials, such as employees, agents, or fiduciaries for the purpose of influencing the bribed individual’s on-the-job conduct. N.Y. Penal Law § 180.00, accessed May 6, 2011, http://law.onecle.com/new-york/penal/PEN0180.00_180.00.html. This type of bribery is typically called commercial bribery Bribery of an employee for the purpose of influencing on-the-job conduct. . N.Y. Penal Law § 180.00, accessed May 6, 2011, http://law.onecle.com/new-york/penal/PEN0180.00_180.00.html. Bribery can also cover members of a state legislature, Cal. Penal Code § 85, accessed May 6, 2011, http://law.onecle.com/california/penal/85.html; Cal. Penal Code § 86, http://law.onecle.com/california/penal/86.html. any judicial officer, juror, referee, umpire, Cal. Penal Code § 92, accessed May 6, 2011, http://law.onecle.com/california/penal/92.html; Cal. Penal Code § 93, http://law.onecle.com/california/penal/93.html. or witness Or. Rev. Stat. § 162.265, accessed May 6, 2011, http://law.onecle.com/oregon/162-offenses-against-the-state-and/162.265.html; Or. Rev. Stat. §162.275, accessed May 7, 2011, http://law.onecle.com/oregon/162-offenses-against-the-state-and/162.275.html. when a bribe is conferred or offered, asked for, received, or agreed to be received to influence their vote or decision. The Model Penal Code criminalizes as bribery the act of conferring, offering, agreeing to confer, soliciting, accepting, or agreeing to accept any pecuniary Monetary. (which means monetary) benefit in exchange for a public servant, party official, voter’s decision, opinion, recommendation, vote, or other exercise of discretion (Model Penal Code § 240.1 (1)). The Model Penal Code also criminalizes as bribery the act of conferring, offering, agreeing to confer, soliciting, accepting, or agreeing to accept any benefit in exchange for a judicial or administrative officer’s decision, vote, recommendation, or other exercise of official discretion (Model Penal Code § 240.1 (2)). Prosecutorial Burden in Bribery Prosecutions Similar to perjury, bribery is notoriously difficult to prove, which is a factor prosecutors must consider when deciding whether or not to charge an individual (s) with this offense. The most difficult bribery element to prove beyond a reasonable doubt is the criminal intent element of specific intent or purposely or general intent or knowingly to enter into an agreement that influences the bribed individual’s decision. Example of Bribery Isabel, a defendant on trial for perjury, notices the judge presiding in her case shopping at Macy’s department store. Isabel thereafter buys an expensive watch, has it wrapped, walks up to the judge, and offers it to him as a gift. Isabel has most likely committed bribery in this case. Although the judge did not accept Isabel’s “gift,” most states criminalize as bribery the offer of any benefit, so the act of bribery is complete when Isabel proffers the watch. In addition, based on these facts, Isabel’s connection to the judge is only through her perjury prosecution, so her act appears calculated to influence his decision in that case, especially because the watch is expensive and not merely a token. Note that a prosecutor is required to prove beyond a reasonable doubt Isabel’s specific intent or purposely or general intent or knowingly to enter into an agreement with the judge influencing his decision, which is challenging even under the obvious circumstances apparent in this case. Another Example of Bribery Review the example with Isabel in Section 13 "Example of Bribery". Add to this example and assume that the judge graciously accepts Isabel’s gift and thereafter rules in her favor, acquitting her of perjury. In this example, both the judge and Isabel have likely committed bribery because most states criminalize the conferring, offering, and accepting and receiving a bribe as the criminal act elements. Thus both Isabel and the judge may be subject to prosecution for and conviction of this offense, and the judge’s acquittal of Isabel will ease the prosecutor’s burden in proving the specific intent or purposely or general intent or knowingly to enter into an agreement corruptly influencing the decision making in this case. Example of a Case Lacking an Element of Bribery Isabel notices a gentleman struggling to pay his bill at a local coffee shop. Isabel steps up and charitably offers to pay the gentleman’s bill. Later in the day, while watching her son’s professional baseball game, Isabel notices that the umpire looks familiar. After pondering it for a few minutes, she realizes that he is the same gentleman who could not pay his bill at the coffee shop. Isabel and the umpire probably have not committed bribery in this case. Although Isabel gave the umpire money, and he was the decision maker in her son’s baseball game, Isabel did not give the money, nor did the umpire accept it, with the specific intent or purposely or general intent or knowingly to enter into an agreement influencing the umpire’s decisions. Thus the criminal intent element for bribery appears to be lacking, and neither Isabel nor the umpire are subject to prosecution for and conviction of this offense. Bribery When No Authority to Act Is Present In many states and under the Model Penal Code, it is no defense to bribery that the individual bribed does not have the authority to act or make the decision that is the subject of the bribe (Model Penal Code § 240.1). Ala. Code § 13A-10-61, accessed May 7, 2011, http://law.onecle.com/alabama/criminal-code/13A-10-61.html. Example of Bribery When No Authority to Act Is Present Review the example with Isabel and the judge in Section 13 "Another Example of Bribery". Change this example and assume that the “judge” in question is an imposter who is merely masquerading as a judge to live out a lifelong fantasy. Isabel and the “judge” may still be prosecuted for and convicted of bribery in many jurisdictions and under the Model Penal Code because lack of authority is typically not a defense to bribery under modern statutes criminalizing this offense. Figure 13.8 Diagram of Defenses to Bribery Bribery Grading Bribery is typically graded as a felony N.Y. Penal Law § 200.00, accessed May 6, 2011, http://law.onecle.com/new-york/penal/PEN0200.00_200.00.html. with enhancements for bribery that is carried out with a larger sum of money N.Y. Penal Law § 200.03, accessed May 6, 2011, http://law.onecle.com/new-york/penal/PEN0200.03_200.03.html. or bribery that results in someone’s prosecution or incarceration for a felony. N.Y. Penal Law § 200.04, accessed May 6, 2011, http://law.onecle.com/new-york/penal/PEN0200.04_200.04.html. When a state legislator Cal. Penal Code § 88, accessed May 7, 2011, http://law.onecle.com/california/penal/88.html. or a public official Cal. Penal Code § 74, accessed May 7, 2011, http://law.onecle.com/california/penal/74.html. commits bribery, it is typical to disqualify that individual from his or her office for life, in addition to any other sentence. Obstruction of Justice Obstruction of justice Interfering with the administration of justice by impeding law enforcement procedure, criminal prosecution, or conviction of criminal defendants. takes many forms and is a classic example of an offense against the administration of justice. States and the federal government exercise broad latitude in enacting statutes that criminalize interference with any aspect of law enforcement procedure or the prosecution and conviction of criminal offenders. Some typical examples of obstruction of justice are as follows: giving false identification to a law enforcement officer, 720 ILCS § 5/31-4.5, accessed May 7, 2011, http://law.onecle.com/illinois/720ilcs5/31-4.5.html. impersonating a law enforcement officer, Fla. Stat. Ann. § 843.08, accessed May 7, 2011, http://law.onecle.com/florida/crimes/843.08.html. refusing to aid a law enforcement officer when requested, N.Y. Penal Law § 195.10, accessed May 7, 2011, http://law.onecle.com/new-york/penal/PEN0195.10_195.10.html. giving false evidence, 720 ILCS § 5/31-4, accessed May 7, 2011, http://law.onecle.com/illinois/720ilcs5/31-4.html. hiding or concealing oneself and refusing to give evidence, 720 ILCS § 5/31-4, accessed May 7, 2011, http://law.onecle.com/illinois/720ilcs5/31-4.html. tampering with evidence, Or. Rev. Stat. § 162.295, accessed May 7, 2011, http://law.onecle.com/oregon/162-offenses-against-the-state-and/162.295.html. and tampering with a witness 18 U.S.C. § 1512, accessed May 7, 2011, http://www.law.cornell.edu/uscode/718/usc_sec_18_00001512----000-.html. or juror. Ariz. Rev. Stat. § 13-2807, accessed May 7, 2011, http://law.onecle.com/arizona/criminal-code/13-2807.html. All these acts are generally supported by specific intent or purposely or general intent or knowingly. The Model Penal Code prohibits threatening unlawful harm to any person or public servant with purpose to influence his decision, opinion, recommendation, vote, or other exercise of discretion (Model Penal Code § 240.2). Obstruction of justice offenses are most often graded as a misdemeanor or felony, depending on the offense. Example of Obstruction of Justice Barry Bonds, a baseball player and record-breaking home run hitter for the San Francisco Giants, was found guilty by a federal jury for obstruction of justice, based on his refusal to answer a question during a grand jury investigation of his steroid use. Juliet Macur, “Bonds Guilty of Obstruction, but Not of Perjury,” New York Times website, accessed May 8, 2011, http://www.nytimes.com/2011/04/14/sports/baseball/14bonds.html?pagewanted=1&_r=1. Bonds was also charged with three counts of perjury, but the jury could not agree to convict, resulting in a mistrial on all three counts. Jorge L. Ortiz, “Verdict in: Bonds Found Guilty, but Case Not Closed Yet,” USA TODAY website, accessed May 8, 2011, http://www.usatoday.com/sports/baseball/2011-04-13-verdict-barry-bonds-guilty_N.htm. The perjury charges stemmed from Bonds’s claim while testifying under oath that he never knowingly used steroids, never knowingly used human growth hormones, and was never injected with a substance by anyone other than his trainer. The obstruction of justice conviction resulted from Bonds’s evasive answer to the question of whether his personal trainer had ever injected him with steroids. Juliet Macur, “Bonds Guilty of Obstruction, but Not of Perjury,” New York Times website, accessed May 8, 2011, http://www.nytimes.com/2011/04/14/sports/baseball/14bonds.html?pagewanted=1&_r=1. Instead of answering yes or no to this question, Bonds began reminiscing about his friendship with the trainer, who went to prison four times in five years for also refusing to testify in the investigation. Juliet Macur, “Bonds Guilty of Obstruction, but Not of Perjury,” New York Times website, accessed May 8, 2011, http://www.nytimes.com/2011/04/14/sports/baseball/14bonds.html?pagewanted=1&_r=1. The perjury charges support the obstruction of justice charge, so the defense asked for a court dismissal of the obstruction of justice conviction in order to clear the way for an appeal. Jorge L. Ortiz, “Verdict in: Bonds Found Guilty, but Case Not Closed Yet,” USA TODAY website, accessed May 8, 2011, http://www.usatoday.com/sports/baseball/2011-04-13-verdict-barry-bonds-guilty_N.htm. Note that Bonds’s obstruction of justice charge of evading the question and refusing to give evidence appears easier to prove than the perjury charges, which have a daunting criminal intent requirement, as discussed in Section 13 "Perjury Criminal Intent". The Barry Bonds Verdict Video Associated Press: Bonds Guilty of Obstruction, Jury Hung on Others The verdict in the federal Barry Bonds case is explained in this video: (click to see video) Additional Crimes against the Government Additional crimes against the government that impair the orderly administration of justice are contempt, N.C. Gen. Stat. § 5A-11, et seq., accessed May 8, 2011, http://law.onecle.com/north-carolina/5a-contempt/index.html. resisting arrest, 18 Pa. Cons. Stat. Ann. § 5104, accessed May 8, 2011, http://law.onecle.com/pennsylvania/crimes-and-offenses/00.051.004.000.html. and escape. Tex. Penal Code § 38.06, accessed May 8, 2011, http://law.onecle.com/texas/penal/38.06.00.html. Review the statutes in the endnotes for common elements and grading of these offenses. Figure 13.9 Diagram of Perjury, Bribery, and Obstruction of Justice Key Takeaways Most jurisdictions define perjury as a false material statement (criminal act), made with specific intent or purposely to deceive, or the general intent or knowingly that the statement was false, in a judicial or official proceeding, or in a certified writing (attendant circumstance), under oath (attendant circumstance). The issues commonly encountered in any perjury prosecution are proving the validity of the oath, the defendant’s criminal intent, or the materiality of the false statement, and any requirement of corroborative evidence. Many jurisdictions provide a defense to perjury if the defendant retracts his or her false statement in the course of the same proceeding in which it was made before it becomes manifest that the falsification will be exposed. Perjury by inconsistent statements is when the defendant makes statements that are inconsistent (criminal act), in a judicial proceeding (attendant circumstance), after taking a validly administered oath (attendant circumstance). The prosecution does not need to prove which statement is false for this offense. Subornation of perjury is procuring another to commit perjury (criminal act), with specific intent or purposely, or general intent or knowingly, and factually and legally causing the resulting harm that perjury is actually committed. Perjury is generally graded as a felony, with a potential sentencing enhancement for committing perjury that causes another to be sentenced to prison or the death penalty. Subornation of perjury is also graded as a felony. Many criminal statutes define bribery as conferring, offering, agreeing to confer, or soliciting, accepting, or agreeing to accept, any benefit upon a public official (criminal act) with the specific intent or purposely, or the general intent or knowingly to form an agreement or understanding that the public official’s decision making will be influenced by the benefit. The crime of bribery is often extended to apply to persons other than public officials, such as employees, agents, or fiduciaries for the purpose of influencing the bribed individual’s on-the-job conduct, which is called commercial bribery. Bribery can also cover members of a state legislature, any judicial officer, juror, referee, umpire, or witness. The primary issue in a bribery prosecution is proving the defendant’s criminal intent to enter into an agreement that influences the bribed individual’s decision making. Bribery is typically graded as a felony, with enhancements for a bribe that is a large sum of money or bribery that results in incarceration for a felony, along with a disqualification from office. Some typical examples of obstruction of justice are as follows: giving false identification to a law enforcement officer, impersonating a law enforcement officer, refusing to aid a law enforcement officer when requested, giving false evidence, hiding or concealing oneself and refusing to give evidence, tampering with evidence, and tampering with a witness or juror. All these acts are generally supported by specific intent or purposely, or general intent or knowingly. Obstruction of justice is graded anywhere from a misdemeanor to a felony, depending on the offense. Exercises Answer the following questions. Check your answers using the answer key at the end of the chapter. Susannah, a Hollywood movie star, is a witness in a civil personal injury case. Susannah saw a car accident and is subpoenaed to testify that the defendant was at fault. After the court commissioner administers an oath to tell the truth, Susannah takes the witness stand. She knows the case will generate significant publicity, so Susannah shaves ten years off of her age when asked routine background questions by the prosecutor. If Susannah is thereafter caught in this lie and prosecuted for perjury, what will be the primary issue in her perjury prosecution? How will this issue be resolved? Read State v. Carr, 172 Conn. 458 (1977). In this case, the defendant was convicted of bribery when he paid an undercover detective to refrain from investigating narcotics crimes in the area. The defendant appealed, claiming the jury should have been instructed on the lesser included offense of offering gifts to state police officers. Did the Supreme Court of Connecticut uphold the defendant’s bribery conviction? Why or why not? The case is available at this link: http://scholar.google.com/scholar_case?case=14705028387089517508&q= %22State+v.+Carr%22&hl=en&as_sdt=2,5. Read People v. Silverberg, 771 N.Y.S. 2d 274 (2003). In this case, the defendant was convicted of witness tampering for a single telephone call he made to an attorney that implied he would send letters to a grievance committee if the attorney did not drop charges against him. Did the Supreme Court of New York uphold the defendant’s conviction? Why or why not? The case is available at this link: http://scholar.google.com/scholar_case?case=3089258849772766127&q= %22witness+tampering%22&hl=en&as_sdt=4,33&as_ylo=2003. Law and Ethics Should Former President Clinton Have Been Criminally Prosecuted for Perjury and Obstruction of Justice? On May 6, 1994, Paula Jones filed a civil lawsuit for sexual harassment against then-president Bill Clinton. The US Supreme Court ruled that the president was not immune to this lawsuit, allowing it to continue. Clinton v. Jones, 520 U.S. 681 (1997), accessed May 9, 2011, http://www.law.cornell.edu/supct/html/95-1853.ZS.html. An investigation pursuant to the Jones lawsuit revealed that the president was currently having an affair with a White House intern, Monica Lewinsky. “Presidential Impeachment Proceedings,” Historyplace.com website, accessed May 9, 2011, http://www.historyplace.com/unitedstates/impeachments/clinton.htm. During a Jones lawsuit deposition, the president stated under oath that he did not have sexual relations with Ms. Lewinsky pursuant to the definition of sexual relations given by the questioning attorneys. Deposition excerpts, Jones v. Clinton deposition, Historyplace.com website, accessed May 9, 2011, http://www.historyplace.com/unitedstates/impeachments/jones-deposition.htm. He also stated that he could not recall ever being alone with Lewinsky at the White House. Deposition excerpts, Jones v. Clinton deposition, Historyplace.com website, accessed May 9, 2011, http://www.historyplace.com/unitedstates/impeachments/jones-deposition.htm. After the deposition, he was involved in an effort to get Ms. Lewinsky a federal job outside Washington, DC. “Presidential Impeachment Proceedings,” Historyplace.com website, accessed May 9, 2011, http://www.historyplace.com/unitedstates/impeachments/clinton.htm. Although the Jones lawsuit was dismissed, the president was evasive when asked questions regarding the Lewinsky affair during a grand jury investigation instigated by Prosecutor and former Solicitor General Kenneth Starr. The evening of the grand jury investigation, the president appeared on national TV and admitted, “Indeed, I did have a relationship with Ms. Lewinsky that was not appropriate. In fact, it was wrong. It constituted a critical lapse in judgment and a personal failure on my part for which I am solely and completely responsible.” “Presidential Impeachment Proceedings,” Historyplace.com website, accessed May 9, 2011, http://www.historyplace.com/unitedstates/impeachments/clinton.htm. The House of Representatives later impeached Clinton for perjury and obstruction of justice, based on the statements he made at the grand jury investigation and his conduct during the Jones deposition. After a trial in the Senate, he was acquitted of both counts and thereafter served out his term as president. “Presidential Impeachment Proceedings,” Historyplace.com website, accessed May 9, 2011, http://www.historyplace.com/unitedstates/impeachments/clinton.htm. He was never criminally prosecuted for perjury or obstruction of justice outside the impeachment procedure, although he was later disbarred for his behavior. Ann Gearan, “Clinton Disbarred by Supreme Court,” Famguardian.org website, accessed May 9, 2011, http://famguardian.org/Subjects/LawAndGovt/News/ClintonDisbar-011001.htm. Is it ethical to allow the president to avoid a criminal prosecution for perjury and obstruction of justice while he is in office? Why or why not? Check your answer using the answer key at the end of the chapter. Clinton Declaration and Admission Videos Clinton: “I did not have sexual relations with that woman…” In this video, President Clinton denies that he had sexual relations with Monica Lewinsky: (click to see video) President Clinton Apologizes to the Nation In this video, President Clinton admits that he had an inappropriate relationship with Monica Lewinsky: (click to see video)	msmarco_doc_00_12069085
http://2012books.lardbucket.org/books/macroeconomics-principles-v1.0/s15-02-the-use-of-fiscal-policy-to-st.html	The Use of Fiscal Policy to Stabilize the Economy	12.2 The Use of Fiscal Policy to Stabilize the Economy 12.2 The Use of Fiscal Policy to Stabilize the Economy Learning Objectives Automatic Stabilizers Discretionary Fiscal Policy Tools Changes in Government Purchases Changes in Business Taxes Changes in Income Taxes Changes in Transfer Payments Key Takeaways Try It! Case in Point: Post–World War II Experiences with Fiscal Policy in the United States Answer to Try It! Problem	The Use of Fiscal Policy to Stabilize the Economy 12.2 The Use of Fiscal Policy to Stabilize the Economy Learning Objectives Define automatic stabilizers and explain how they work. Explain and illustrate graphically how discretionary fiscal policy works and compare the changes in aggregate demand that result from changes in government purchases, income taxes, and transfer payments. Fiscal policy—the use of government expenditures and taxes to influence the level of economic activity—is the government counterpart to monetary policy. Like monetary policy, it can be used in an effort to close a recessionary or an inflationary gap. Some tax and expenditure programs change automatically with the level of economic activity. We will examine these first. Then we will look at how discretionary fiscal policies work. Four examples of discretionary fiscal policy choices were the tax cuts introduced by the Kennedy, Reagan, and George W. Bush administrations and the increase in government purchases proposed by President Clinton in 1993. The 2009 fiscal stimulus bill passed in the first months of the administration of Barack Obama included both tax cuts and spending increases. All were designed to stimulate aggregate demand and close recessionary gaps. Automatic Stabilizers Certain government expenditure and taxation policies tend to insulate individuals from the impact of shocks to the economy. Transfer payments have this effect. Because more people become eligible for income supplements when income is falling, transfer payments reduce the effect of a change in real GDP on disposable personal income and thus help to insulate households from the impact of the change. Income taxes also have this effect. As incomes fall, people pay less in income taxes. Any government program that tends to reduce fluctuations in GDP automatically is called an automatic stabilizer Any government program that tends to reduce fluctuations in GDP automatically. . Automatic stabilizers tend to increase GDP when it is falling and reduce GDP when it is rising. To see how automatic stabilizers work, consider the decline in real GDP that occurred during the recession of 1990–1991. Real GDP fell 1.6% from the peak to the trough of that recession. The reduction in economic activity automatically reduced tax payments, reducing the impact of the downturn on disposable personal income. Furthermore, the reduction in incomes increased transfer payment spending, boosting disposable personal income further. Real disposable personal income thus fell by only 0.9% during the 2001 recession, a much smaller percentage than the reduction in real GDP. Rising transfer payments and falling tax collections helped cushion households from the impact of the recession and kept real GDP from falling as much as it would have otherwise. Automatic stabilizers have emerged as key elements of fiscal policy. Increases in income tax rates and unemployment benefits have enhanced their importance as automatic stabilizers. The introduction in the 1960s and 1970s of means-tested federal transfer payments, in which individuals qualify depending on their income, added to the nation’s arsenal of automatic stabilizers. The advantage of automatic stabilizers is suggested by their name. As soon as income starts to change, they go to work. Because they affect disposable personal income directly, and because changes in disposable personal income are closely linked to changes in consumption, automatic stabilizers act swiftly to reduce the degree of changes in real GDP. It is important to note that changes in expenditures and taxes that occur through automatic stabilizers do not shift the aggregate demand curve. Because they are automatic, their operation is already incorporated in the curve itself. Discretionary Fiscal Policy Tools As we begin to look at deliberate government efforts to stabilize the economy through fiscal policy choices, we note that most of the government’s taxing and spending is for purposes other than economic stabilization. For example, the increase in defense spending in the early 1980s under President Ronald Reagan and in the administration of George W. Bush were undertaken primarily to promote national security. That the increased spending affected real GDP and employment was a by-product. The effect of such changes on real GDP and the price level is secondary, but it cannot be ignored. Our focus here, however, is on discretionary fiscal policy that is undertaken with the intention of stabilizing the economy. As we have seen, the tax cuts introduced by the Bush administration were justified as expansionary measures. Discretionary government spending and tax policies can be used to shift aggregate demand. Expansionary fiscal policy might consist of an increase in government purchases or transfer payments, a reduction in taxes, or a combination of these tools to shift the aggregate demand curve to the right. A contractionary fiscal policy might involve a reduction in government purchases or transfer payments, an increase in taxes, or a mix of all three to shift the aggregate demand curve to the left. Figure 12.8 "Expansionary and Contractionary Fiscal Policies to Shift Aggregate Demand" illustrates the use of fiscal policy to shift aggregate demand in response to a recessionary gap and an inflationary gap. In Panel (a), the economy produces a real GDP of Y1, which is below its potential level of Yp. An expansionary fiscal policy seeks to shift aggregate demand to AD2 in order to close the gap. In Panel (b), the economy initially has an inflationary gap at Y1. A contractionary fiscal policy seeks to reduce aggregate demand to AD2 and close the gap. Now we shall look at how specific fiscal policy options work. In our preliminary analysis of the effects of fiscal policy on the economy, we will assume that at a given price level these policies do not affect interest rates or exchange rates. We will relax that assumption later in the chapter. Figure 12.8 Expansionary and Contractionary Fiscal Policies to Shift Aggregate Demand In Panel (a), the economy faces a recessionary gap ( YP − Y1 ). An expansionary fiscal policy seeks to shift aggregate demand to AD2 to close the gap. In Panel (b), the economy faces an inflationary gap ( Y1 − YP ). A contractionary fiscal policy seeks to reduce aggregate demand to AD2 to close the gap. Changes in Government Purchases One policy through which the government could seek to shift the aggregate demand curve is a change in government purchases. We learned that the aggregate demand curve shifts to the right by an amount equal to the initial change in government purchases times the multiplier. This multiplied effect of a change in government purchases occurs because the increase in government purchases increases income, which in turn increases consumption. Then, part of the impact of the increase in aggregate demand is absorbed by higher prices, preventing the full increase in real GDP that would have occurred if the price level did not rise. Figure 12.9 "An Increase in Government Purchases" shows the effect of an increase in government purchases of $200 billion. The initial price level is P1 and the initial equilibrium real GDP is $12,000 billion. Suppose the multiplier is 2. The $200 billion increase in government purchases increases the total quantity of goods and services demanded, at a price level of P1, by $400 billion (the $200 billion increase in government purchases times the multiplier) to $12,400 billion. The aggregate demand thus shifts to the right by that amount to AD2. The equilibrium level of real GDP rises to $12,300 billion, and the price level rises to P2. Figure 12.9 An Increase in Government Purchases The economy shown here is initially in equilibrium at a real GDP of $12,000 billion and a price level of P1. An increase of $200 billion in the level of government purchases (Δ G) shifts the aggregate demand curve to the right by $400 billion to AD2. The equilibrium level of real GDP rises to $12,300 billion, while the price level rises to P2. A reduction in government purchases would have the opposite effect. The aggregate demand curve would shift to the left by an amount equal to the initial change in government purchases times the multiplier. Real GDP and the price level would fall. Changes in Business Taxes One of the first fiscal policy measures undertaken by the Kennedy administration in the 1960s was an investment tax credit. An investment tax credit allows a firm to reduce its tax liability by a percentage of the investment it undertakes during a particular period. With an investment tax credit of 10%, for example, a firm that engaged in $1 million worth of investment during a year could reduce its tax liability for that year by $100,000. The investment tax credit introduced by the Kennedy administration was later repealed. It was reintroduced during the Reagan administration in 1981, then abolished by the Tax Reform Act of 1986. President Clinton called for a new investment tax credit in 1993 as part of his job stimulus proposal, but that proposal was rejected by Congress. The Bush administration reinstated the investment tax credit as part of its tax cut package. An investment tax credit is intended, of course, to stimulate additional private sector investment. A reduction in the tax rate on corporate profits would be likely to have a similar effect. Conversely, an increase in the corporate income tax rate or a reduction in an investment tax credit could be expected to reduce investment. A change in investment affects the aggregate demand curve in precisely the same manner as a change in government purchases. It shifts the aggregate demand curve by an amount equal to the initial change in investment times the multiplier. An increase in the investment tax credit, or a reduction in corporate income tax rates, will increase investment and shift the aggregate demand curve to the right. Real GDP and the price level will rise. A reduction in the investment tax credit, or an increase in corporate income tax rates, will reduce investment and shift the aggregate demand curve to the left. Real GDP and the price level will fall. Investment also affects the long-run aggregate supply curve, since a change in the capital stock changes the potential level of real GDP. We examined this earlier in the chapter on economic growth. Changes in Income Taxes Income taxes affect the consumption component of aggregate demand. An increase in income taxes reduces disposable personal income and thus reduces consumption (but by less than the change in disposable personal income). That shifts the aggregate demand curve leftward by an amount equal to the initial change in consumption that the change in income taxes produces times the multiplier. A change in tax rates will change the value of the multiplier. The reason is explained in another chapter. A reduction in income taxes increases disposable personal income, increases consumption (but by less than the change in disposable personal income), and increases aggregate demand. Suppose, for example, that income taxes are reduced by $200 billion. Only some of the increase in disposable personal income will be used for consumption and the rest will be saved. Suppose the initial increase in consumption is $180 billion. Then the shift in the aggregate demand curve will be a multiple of $180 billion; if the multiplier is 2, aggregate demand will shift to the right by $360 billion. Thus, as compared to the $200-billion increase in government purchases that we saw in Figure 12.9 "An Increase in Government Purchases", the shift in the aggregate demand curve due to an income tax cut is somewhat less, as is the effect on real GDP and the price level. Changes in Transfer Payments Changes in transfer payments, like changes in income taxes, alter the disposable personal income of households and thus affect their consumption, which is a component of aggregate demand. A change in transfer payments will thus shift the aggregate demand curve because it will affect consumption. Because consumption will change by less than the change in disposable personal income, a change in transfer payments of some amount will result in a smaller change in real GDP than would a change in government purchases of the same amount. As with income taxes, a $200-billion increase in transfer payments will shift the aggregate demand curve to the right by less than the $200-billion increase in government purchases that we saw in Figure 12.9 "An Increase in Government Purchases". Table 12.3 "Fiscal Policy in the United States Since 1964" summarizes U.S. fiscal policies undertaken to shift aggregate demand since the 1964 tax cuts. We see that expansionary policies have been chosen in response to recessionary gaps and that contractionary policies have been chosen in response to inflationary gaps. Changes in government purchases and in taxes have been the primary tools of fiscal policy in the United States. Table 12.3 Fiscal Policy in the United States Since 1964 Year Situation Policy response 1968 Inflationary gap A temporary tax increase, first recommended by President Johnson’s Council of Economic Advisers in 1965, goes into effect. This one-time surcharge of 10% is added to individual income tax liabilities. 1969 Inflationary gap President Nixon, facing a continued inflationary gap, orders cuts in government purchases. 1975 Recessionary gap President Ford, facing a recession induced by an OPEC oil-price increase, proposes a temporary 10% tax cut. It is passed almost immediately and goes into effect within two months. 1981 Recessionary gap President Reagan had campaigned on a platform of increased defense spending and a sharp cut in income taxes. The tax cuts are approved in 1981 and are implemented over a period of three years. The increased defense spending begins in 1981. While the Reagan administration rejects the use of fiscal policy as a stabilization tool, its policies tend to increase aggregate demand early in the 1980s. 1992 Recessionary gap President Bush had rejected the use of expansionary fiscal policy during the recession of 1990–1991. Indeed, he agreed late in 1990 to a cut in government purchases and a tax increase. In a campaign year, however, he orders a cut in withholding rates designed to increase disposable personal income in 1992 and to boost consumption. 1993 Recessionary gap President Clinton calls for a $16-billion jobs package consisting of increased government purchases and tax cuts aimed at stimulating investment. The president says the plan will create 500,000 new jobs. The measure is rejected by Congress. 2001 Recessionary gap President Bush campaigned to reduce taxes in order to reduce the size of government and encourage long-term growth. When he took office in 2001, the economy was weak and the $1.35-billion tax cut was aimed at both long-term tax relief and at stimulating the economy in the short term. It included, for example, a personal income tax rebate of $300 to $600 per household. With unemployment still high a couple of years into the expansion, another tax cut was passed in 2003. 2008 Recessionary gap Fiscal stimulus package of $150 billion to spur economy. It included $100 billion in tax rebates and $50 in tax cuts for businesses. 2009 Recessionary gap Fiscal stimulus package of $787 billion included tax cuts and increased government spending passed in early days of President Obama’s administration. Key Takeaways Discretionary fiscal policy may be either expansionary or contractionary. A change in government purchases shifts the aggregate demand curve at a given price level by an amount equal to the initial change in government purchases times the multiplier. The change in real GDP, however, will be reduced by the fact that the price level will change. A change in income taxes or government transfer payments shifts the aggregate demand curve by a multiple of the initial change in consumption (which is less than the change in personal disposable income) that the change in income taxes or transfer payments causes. Then, the change in real GDP will be reduced by the fact that the price level will change. A change in government purchases has a larger impact on the aggregate demand curve than does an equal change in income taxes or transfers. Changes in business tax rates, including an investment tax credit, can be used to influence the level of investment and thus the level of aggregate demand. Try It! Suppose the economy has an inflationary gap. What fiscal policies might be used to close the gap? Using the model of aggregate demand and aggregate supply, illustrate the effect of these policies. Case in Point: Post–World War II Experiences with Fiscal Policy in the United States Figure 12.10 Christina Romer, tapped by Barack Obama to head the Council of Economic Advisers, has a long history of writing on economic history. Much of her work focuses on the macroeconomic performance of the United States economy over the past 100-plus years and hence also involves painstaking work to construct historical data series. One such study titled “Changes in Business Cycles: Evidence and Explanations” draws on a number of her research efforts to compare economic fluctuations before World War I to those after World War II in order to see if the advent of macroeconomic stabilization policy has affected macroeconomic performance. After first showing that macroeconomic performance has not improved as markedly as we might think (excluding the interwar period when “all hell broke loose in the American economy”), she does conclude that monetary and fiscal policies to influence aggregate demand since World War II have “served to dampen many recessions and counteract some shocks entirely.” She notes that before World War I, changes in macroeconomic policy could not have affected economic performance, because the government was simply too small, with, for example, government spending as a percent of GNP averaging between 1.5% and 2.5% between 1901 and 1916. During that period, the government did operate under specified monetary standards and banking regulations, but the Federal Reserve was not created until 1914, so there was no monetary institution to respond to macroeconomic instability. Thus, macroeconomic policy can truly be seen as a post–World War II phenomenon. Germaine to the focus on fiscal policy in this chapter, Romer found that discretionary fiscal policy after World War II contributed 0.5 percentage points to the rate of growth of real GDP in years following the troughs of recessions, while automatic stabilizers contributed 0.85 percentage points. Adding in the average contribution of monetary policy of 1.5 percentage points, macroeconomic policy in total contributed 2.85 percentage points to the average actual growth of GDP in the years following troughs of 4.6%. She also concluded that macroeconomic policies likely prevented some recessions or near-recessions. For example, automatic stabilizers muted fluctuations in years of extreme changes in GDP, up or down, by 1 to 2 percentage points in absolute value and fluctuations in years of moderate changes in GDP by about 0.5 percentage points in absolute value. Especially in light of the active use of both monetary and fiscal policies to counter the recession that began in December 2007, she also found that there has been a rise in policy-induced recessions and that this phenomenon explains both why output and other macroeconomic variables have not been more stable in the past half-century and why post–World War II business cycles have been in the moderate range. In particular, she argues that the Fed has generally been too expansionary when the economy was growing, which has led to inflation. Then the Fed has used contractionary policy to reduce inflation. She concludes, “In essence, we have replaced the prewar boom-bust cycle driven by animal spirits and financial panics with the postwar boom-bust cycle driven by policy.” Source: Christina Romer, “Changes in Business Cycles: Evidence and Explanations,” Journal of Economic Perspectives 13, no. 2 (Spring 1999): 23–44. Answer to Try It! Problem Fiscal policies that could be used to close an inflationary gap include reductions in government purchases and transfer payments and increases in taxes. As shown in Panel (b) of Figure 12.8 "Expansionary and Contractionary Fiscal Policies to Shift Aggregate Demand", the goal would be to shift the aggregate demand curve to the left so that it will intersect the short-run aggregate supply curve at YP.	msmarco_doc_00_12109077
http://2012books.lardbucket.org/books/macroeconomics-principles-v2.0/s08-01-growth-of-real-gdp-and-busines.html	Growth of Real GDP and Business Cycles	5.1 Growth of Real GDP and Business Cycles 5.1 Growth of Real GDP and Business Cycles Learning Objectives Phases of the Business Cycle Business Cycles and the Growth of Real GDP in the United States Key Takeaways Try It! Case in Point: The Art of Predicting Recessions Answer to Try It! Problem	Growth of Real GDP and Business Cycles 5.1 Growth of Real GDP and Business Cycles Learning Objectives Define real gross domestic product and explain how its calculation avoids both double-counting and the effects of changes in the price level. Identify the phases of a business cycle. Relate business cycles to the overall long-run trend in real GDP in the United States. To determine whether the economy of a nation is growing or shrinking in size, economists use a measure of total output called real GDP. Real GDP The total value of all final goods and services produced during a particular year or period, adjusted to eliminate the effects of changes in prices. , short for real gross domestic product, is the total value of all final goods and services produced during a particular year or period, adjusted to eliminate the effects of changes in prices. Let us break that definition up into parts. Notice that only “final” goods and services are included in GDP. Many goods and services are purchased for use as inputs in producing something else. For example, a pizza parlor buys flour to make pizzas. If we counted the value of the flour and the value of the pizza, we would end up counting the flour twice and thus overstating the value of total production. Including only final goods avoids double-counting. If the flour is produced during a particular period but has not been sold, then it is a “final good” for that period and is counted. We want to determine whether the economy’s output is growing or shrinking. If each final good or service produced, from hammers to haircuts, were valued at its current market price, and then we were to add the values of all such items produced, we would not know if the total had changed because output changed or because prices changed or both. The market value of all final goods and services produced can rise even if total output falls. To isolate the behavior of total output only, we must hold prices constant at some level. For example, if we measure the value of basketball output over time using a fixed price for valuing the basketballs, then only an increase in the number of basketballs produced could increase the value of the contribution made by basketballs to total output. By making such an adjustment for basketballs and all other goods and services, we obtain a value for real GDP. In contrast, nominal GDP The total value of final goods and services for a particular period valued in terms of prices for that period. , usually just referred to as gross domestic product (GDP), is the total value of final goods and services for a particular period valued in terms of prices for that period. For example, real GDP fell in the third quarter of 2008. But, because the price level in the United States was rising, nominal GDP rose 3.6%. We will save a detailed discussion of the computation of GDP for another chapter. In this section, our goal is to use the concept of real GDP to look at the business cycle The economy’s pattern of expansion, then contraction, then expansion again. —the economy’s pattern of expansion, then contraction, then expansion again—and at growth of real GDP. Phases of the Business Cycle Figure 5.1 "Phases of the Business Cycle" shows a stylized picture of a typical business cycle. It shows that economies go through periods of increasing and decreasing real GDP, but that over time they generally move in the direction of increasing levels of real GDP. A sustained period in which real GDP is rising is an expansion A sustained period in which real GDP is rising. ; a sustained period in which real GDP is falling is a recession A sustained period in which real GDP is falling. . Typically, an economy is said to be in a recession when real GDP drops for two consecutive quarters, but in the United States, the responsibility of defining precisely when the economy is in recession is left to the Business Cycle Dating Committee of the National Bureau of Economic Research (NBER). The committee defines a recession as a “significant decline in economic activity spread across the economy, lasting more than a few months, normally visible in real GDP, real income, employment, industrial production, and wholesale-retail sales.” “The NBER’s Recession Dating Procedure,” National Bureau of Economic Research, January 7, 2008. Figure 5.1 Phases of the Business Cycle The business cycle is a series of expansions and contractions in real GDP. The cycle begins at a peak and continues through a recession, a trough, and an expansion. A new cycle begins at the next peak. Here, the first peak occurs at time t1, the trough at time t2, and the next peak at time t3. Notice that there is a tendency for real GDP to rise over time. At time t1 in Figure 5.1 "Phases of the Business Cycle", an expansion ends and real GDP turns downward. The point at which an expansion ends and a recession begins is called the peak The point of the business cycle at which an expansion ends and a recession begins. of the business cycle. Real GDP then falls during a period of recession. Eventually it starts upward again (at time t2 ). The point at which a recession ends and an expansion begins is called the trough The point of the business cycle at which a recession ends and an expansion begins. of the business cycle. The expansion continues until another peak is reached at time t3. Some economists prefer to break the expansion phase into two parts. The recovery phase is said to be the period between the previous trough and the time when the economy achieves its previous peak level of real GDP. The “expansion” phase is from that point until the following peak. A complete business cycle is defined by the passage from one peak to the next. Because the Business Cycle Dating Committee dates peaks and troughs by specific months, and because real GDP is estimated only on a quarterly basis by the Bureau of Economic Analysis, the committee relies on a variety of other indicators that are published monthly, including real personal income, employment, industrial production, and real wholesale and retail sales. The committee typically determines that a recession has happened long after it has actually begun and sometimes ended! In large part, that avoids problems when data released about the economy are revised, and the committee avoids having to reverse itself on its determination of when a recession begins or ends, something it has never done. In December 2008, the committee announced that a recession in the United States had begun in December 2007. In September 2010, the committee announced that this recession had ended in June 2009. Business Cycles and the Growth of Real GDP in the United States Figure 5.2 "Expansions and Recessions, 1960–2011" shows movements in real GDP in the United States from 1960 to 2011. Over those years, the economy experienced eight recessions, shown by the shaded areas in the chart. Although periods of expansion have been more prolonged than periods of recession, we see the cycle of economic activity that characterizes economic life. Figure 5.2 Expansions and Recessions, 1960–2011 The chart shows movements in real GDP since 1960. Recessions—periods of falling real GDP—are shown as shaded areas. On average, the annual rate of growth of real GDP over the period was 3.1% per year. Source: Bureau of Economic Analysis, NIPA Table 1.1.6 (revised February 29, 2012). Real Gross Domestic Product, Chained Dollars [Billions of chained (2005) dollars]. Seasonally adjusted at annual rates. Real GDP clearly grew between 1960 and 2011. While the economy experienced expansions and recessions, its general trend during the period was one of rising real GDP. The average annual rate of growth of real GDP was about 3.1%. During the post–World War II period, the average expansion has lasted 58 months, and the average recession has lasted about 11 months. The 2001 recession, which lasted eight months, was thus slightly shorter than the average. The 2007–2009 recession lasted 18 months; it was the longest of the post–World War II period. Economists have sought for centuries to explain the forces at work in a business cycle. Not only are the currents that move the economy up or down intellectually fascinating but also an understanding of them is of tremendous practical importance. A business cycle is not just a movement along a curve in a textbook. It is new jobs for people, or the loss of them. It is new income, or the loss of it. It is the funds to build new schools or to provide better health care—or the lack of funds to do all those things. The story of the business cycle is the story of progress and plenty, of failure and sacrifice. During the most recent recession, the job outlook for college graduates deteriorated. According to a National Association of Colleges and Employers study, 20% of college graduates seeking jobs were able to obtain one after graduation in 2009. In 2010, that percentage rose to 24%, but the average salary had slipped 1.7% from the previous year. The unemployment rate for college graduates under age 25 rose from 3.7% in April 2007 to 8% in April 2010. Over the same two-year period, the unemployment rate for high school graduates who had never enrolled in college rose from 11.4% to 24.5%. Steven Greenhouse, “Job Market Gets Better for U.S. Graduates, but Only Slightly: Offers Will Increase 5% Over Last Year; Average Starting Salaries Are Down,” The International Herald Tribune, May 26, 2010, Finance 16. The effects of recessions extend beyond the purely economic realm and influence the social fabric of society as well. Suicide rates and property crimes—burglary, larceny, and motor vehicle theft tend to rise during recessions. Even popular music appears to be affected. Terry F. Pettijohn II, a psychologist at Coastal Carolina University, has studied Billboard No. 1 songs from 1955 to 2003. He finds that during recessions, popular songs tend to be longer and slower, and to have more serious lyrics. “It’s ‘Bridge over Troubled Water’ or ‘That’s What Friends Are For’,” he says. During expansions, songs tend to be faster, shorter, and somewhat sillier, such as “At the Hop” or “My Sharona.” Tamar Lewin, “A Hemline Index, Updated,” New York Times, October 19, 2008, Section WK, 1. In our study of macroeconomics, we will gain an understanding of the forces at work in the business cycle. We will also explore policies through which the public sector might act to make recessions less severe and, perhaps, to prolong expansions. We turn next to an examination of price-level changes and unemployment. Key Takeaways Real gross domestic product (real GDP) is a measure of the value of all final goods and services produced during a particular year or period, adjusted to eliminate the effects of price changes. The economy follows a path of expansion, then contraction, then expansion again. These fluctuations make up the business cycle. The point at which an expansion becomes a recession is called the peak of a business cycle; the point at which a recession becomes an expansion is called the trough. Over time, the general trend for most economies is one of rising real GDP. On average, real GDP in the United States has grown at a rate of over 3% per year since 1960. Try It! The data below show the behavior of real GDP in Turkey from the first quarter of 2001 through the third quarter of 2002. Use the data to plot real GDP in Turkey and indicate the phases of the business cycle. Period Real GDP (billions of New Turkish lira, 1987 prices) First quarter, 2001 24.1 Second quarter, 2001 26.0 Third quarter, 2001 33.1 Fourth quarter, 2001 27.1 First quarter, 2002 24.6 Second quarter, 2002 28.3 Third quarter, 2002 35.7 Case in Point: The Art of Predicting Recessions People who make a living tracking the economy and trying to predict its future do not do a very good job at predicting turning points in economic activity. The 52 economists surveyed by the Wall Street Journal each month did predict that the economy would slip into a recession in the third quarter of 2008. They made that prediction, however, in October—after the third quarter had ended. In September, the last month of the third quarter, the average forecast among the 52 economists had the economy continuing to grow through the third and fourth quarters of 2008. That September survey was taken before the financial crisis hit, a crisis that took virtually everyone by surprise. Of course, as we have already noted, the third-quarter downturn had not been identified as a recession by the NBER’s Business Cycle Dating Committee as of November of 2008. Predicting business cycle turning points has always been a tricky business. The experience of the recession of 2001 illustrates this. As the accompanying table shows, even as late as September 10, 2001, only 13 out of the 100 Blue Chip forecasters had answered in the affirmative to the question, “Has the United States slipped into a recession?” even though we now know the recession had begun the previous March. Comparing the data that were originally released by the U.S. Bureau of Economic Analysis shortly after the end of each quarter with the revised data that were released after July 2002 provides an important insight into explaining why the forecasters seem to have done so badly. As the graph on pre-revision and post-revision estimates of real GDP growth shows, the data released shortly after the end of each quarter showed an economy expanding through the second quarter of 2001, whereas the revised data show the economy contracting modestly in the first quarter of 2001 and then more forcefully in the second quarter. Only after the attacks on the World Trade Center in New York City and the Pentagon in Washington, D.C., on September 11, 2001, did most of the Blue Chip forecasters realize the economy was in recession. The National Bureau of Economic Research (NBER) Business Cycle Dating Committee in November 2001 released a press announcement dating the onset of the recession as March 2001. The committee argued that “before the attacks of September 11, it is possible that the decline in the economy would have been too mild to qualify as a recession. The attacks clearly deepened the contraction and may have been an important factor in turning the episode into a recession.” While surprising at the time, the revised data suggest that the committee made a good call. This episode in economic history also points out the difference between the common definition of a recession as two consecutive quarters of declining real GDP and the NBER Dating Committee’s continued insistence that it does not define a recession in this way. Rather the committee looks not only at real GDP but also at employment, income, and other factors. The behavior of employment during 2001 seems to have been an important factor in the November 2001 decision to proclaim March 2001 as the peak despite the misleading information on real GDP coming out of the Bureau of Economic Analysis at the time. The slow pickup in employment may also, though, have made it hesitate to call November 2001 the trough until July 2003. Question posed: “Has the United States slipped into a recession?” Date Percent of Blue Chip responders answering “Yes” Percent of Blue Chip responders answering “No” February 2001 5 95 June 2001 7 93 July 2001 13 87 August 2001 5 85 September 10, 2001 13 87 September 19, 2001 82 18 Sources: Phil Izzo, “Economists Expect Crisis to Deepen,” Wall Street Journal Online, October 10, 2008; Kevin L. Kliesen, “The 2001 Recession: How Was It Different and What Developments May Have Caused It?” Federal Reserve Bank of St. Louis Review, September/October 2003: 23–37; http://www.nber.org/cycles/; “Press Release,” Business Cycle Dating Committee, National Bureau of Economic Research, press release, Cambridge, Massachusetts, July 17, 2002. Answer to Try It! Problem	msmarco_doc_00_12130634
http://2012books.lardbucket.org/books/managerial-economics-principles/s02-03-revenue-cost-and-profit-functi.html	Revenue, Cost, and Profit Functions	2.3 Revenue, Cost, and Profit Functions 2.3 Revenue, Cost, and Profit Functions	Revenue, Cost, and Profit Functions 2.3 Revenue, Cost, and Profit Functions In the preceding projections for the proposed ice cream bar venture, the assumption was that 36,000 ice cream bars would be sold based on the volume in the prior summer. However, the actual volume for a future venture might be higher or lower. And with an economic profit so close to zero, our students should consider the impact of any such differences. There is a relationship between the volume or quantity created and sold and the resulting impact on revenue, cost, and profit. These relationships are called the revenue function, cost function, and profit function. These relationships can be expressed in terms of tables, graphs, or algebraic equations. In a case where a business sells one kind of product or service, revenue is the product of the price per unit times the number of units sold. If we assume ice cream bars will be sold for $1.50 apiece, the equation for the revenue function The product of the price per unit times the number of units sold; R = PQ. will be R = $1.5 Q, where R is the revenue and Q is the number of units sold. The cost function The sum of fixed cost and the product of the variable cost per unit times quantity of units produced, also called total cost; C = F + VQ. for the ice cream bar venture has two components: the fixed cost component of $40,000 that remains the same regardless of the volume of units and the variable cost component of $0.30 times the number of items. The equation for the cost function is C = $40,000 + $0.3 Q, where C is the total cost. Note we are measuring economic cost, not accounting cost. Since profit is the difference between revenue and cost, the profit functions The revenue function minus the cost function; in symbols π = R - C = (PQ) - (F + VQ). will be π = R − C = $1.2 Q − $40,000. Here π is used as the symbol for profit. (The letter P is reserved for use later as a symbol for price.) Table 2.1 "Revenue, Cost, and Profit for Selected Sales Volumes for Ice Cream Bar Venture" provides actual values for revenue, cost, and profit for selected values of the volume quantity Q. Figure 2.1 "Graphs of Revenue, Cost, and Profit Functions for Ice Cream Bar Business at Price of $1.50", provides graphs of the revenue, cost, and profit functions. The average cost The total cost divided by the quantity produced; AC = C/Q. is another interesting measure to track. This is calculated by dividing the total cost by the quantity. The relationship between average cost and quantity is the average cost function. For the ice cream bar venture, the equation for this function would be AC = C/Q = ($40,000 + $0.3 Q)/Q = $0.3 + $40,000/Q. Figure 2.2 "Graph of Average Cost Function for Ice Cream Bar Venture" shows a graph of the average cost function. Note that the average cost function starts out very high but drops quickly and levels off. Table 2.1 Revenue, Cost, and Profit for Selected Sales Volumes for Ice Cream Bar Venture Units Revenue Cost Profit 0 $0 $40,000 –$40,000 10,000 $15,000 $43,000 –$28,000 20,000 $30,000 $46,000 –$16,000 30,000 $45,000 $49,000 –$4,000 40,000 $60,000 $52,000 $8,000 50,000 $75,000 $55,000 $20,000 60,000 $90,000 $58,000 $32,000 Figure 2.1 Graphs of Revenue, Cost, and Profit Functions for Ice Cream Bar Business at Price of $1.50 Essentially the average cost function is the variable cost per unit of $0.30 plus a portion of the fixed cost allocated across all units. For low volumes, there are few units to spread the fixed cost, so the average cost is very high. However, as the volume gets large, the fixed cost impact on average cost becomes small and is dominated by the variable cost component. Figure 2.2 Graph of Average Cost Function for Ice Cream Bar Venture	msmarco_doc_00_12147487
http://2012books.lardbucket.org/books/marketing-principles-v1.0/s06-consumer-behavior-how-people-m.html	Consumer Behavior: How People Make Buying Decisions	Chapter 3 Consumer Behavior: How People Make Buying Decisions Chapter 3 Consumer Behavior: How People Make Buying Decisions 3.1 The Consumer’s Decision-Making Process Stages in the Buying Process Stage 1. Need Recognition Stage 2. Search for Information Stage 3. Product Evaluation Stage 4. Product Choice and Purchase Stage 5. Postpurchase Use and Evaluation Stage 6. Disposal of the Product Low-Involvement versus High-Involvement Buying Decisions Video Clip 3.2 Situational Factors That Affect People’s Buying Behavior The Consumer’s Physical Situation The Consumer’s Social Situation Video Clip The Consumer’s Time Situation The Reason for the Consumer’s Purchase The Consumer’s Mood 3.3 Personal Factors That Affect People’s Buying Behavior The Consumer’s Personality The Consumer’s Self-Concept The Consumer’s Gender Video Clip The Consumer’s Age and Stage of Life The Consumer’s Lifestyle Audio Clip 3.4 Psychological Factors That Affect People’s Buying Behavior Motivation The Consumer’s Perception Video Clip Learning Consumer’s Attitude 3.5 Societal Factors That Affect People’s Buying Behavior The Consumer’s Culture The Consumer’s Subculture (s) The Consumer’s Social Class Reference Groups and Opinion Leaders The Consumer’s Family 3.6 Discussion Questions and Activities Discussion Questions Activities	Consumer Behavior: How People Make Buying Decisions Chapter 3 Consumer Behavior: How People Make Buying Decisions Why do you buy the things you do? How did you decide to go to the college you’re attending? Where do like to shop and when? Do your friends shop at the same places or different places? Marketing professionals want to know the answers to these questions. They know that once they do have those answers, they will have a much better chance of creating and communicating about products that you and people like you will want to buy. That’s what the study of consumer behavior is all about. Consumer behavior The study of when, where, and how people buy things and then dispose of them. considers the many reasons why—personal, situational, psychological, and social—people shop for products, buy and use them, and then dispose of them. Companies spend billions of dollars annually studying what makes consumers “tick.” Although you might not like it, Google, AOL, and Yahoo! monitor your Web patterns—the sites you search, that is. The companies that pay for search advertising Advertising that appears on the Web pages pulled up when online searches are conducted. , or ads that appear on the Web pages you pull up after doing an online search, want to find out what kind of things you’re interested in. Doing so allows these companies to send you popup ads and coupons you might actually be interested in instead of ads and coupons for products such as Depends or Viagra. Massachusetts Institute of Technology (MIT), in conjunction with a large retail center, has tracked consumers in retail establishments to see when and where they tended to dwell, or stop to look at merchandise. How was it done? By tracking the position of the consumers’ mobile phones as the phones automatically transmitted signals to cellular towers. MIT found that when people’s “dwell times” increased, sales increased, too. “The Way the Brain Buys,” Economist, December 20, 2009, 105–7. Researchers have even looked at people’s brains by having them lie in scanners and asking them questions about different products. What people say about the products is then compared to what their brains scans show—that is, what they are really thinking. Scanning people’s brains for marketing purposes might sound nutty. But maybe not when you consider the fact is that eight out of ten new consumer products fail, even when they are test marketed. Could it be that what people say about potentially new products and what they think about them are different? Marketing professionals want to find out. “The Way the Brain Buys,” Economist, December 20, 2009, 105–7. Studying people’s buying habits isn’t just for big companies, though. Even small businesses and entrepreneurs can study the behavior of their customers with great success. For example, by figuring out what zip codes their customers are in, a business might determine where to locate an additional store. Customer surveys and other studies can also help explain why buyers purchased what they did and what their experiences were with a business. Even small businesses such as restaurants use coupon codes. For example, coupons sent out in newspapers are given one code. Those sent out via the Internet are given another. Then when the coupons are redeemed, the restaurants can tell which marketing avenues are having the biggest effect on their sales. Figure 3.1 Tony Hsieh, the chief executive of the shoe company Zappos.com, reportedly has thirty thousand followers on Twitter and his Zappos blog. Dell has begun making millions on Twitter by providing followers with exclusive deals, outlet offers, and product updates. To see the top users of Twitter, go to http://www.twitterholic.com. © Zappos.com, Inc. Some businesses, including a growing number of startups, are using blogs and social networking Web sites to gather information about their customers at a low cost. For example, Proper Cloth, a company based in New York, has a site on the social networking site Facebook. Whenever the company posts a new bulletin or photos of its clothes, all its Facebook “fans” automatically receive the information on their own Facebook pages. “We want to hear what our customers have to say,” says Joseph Skerritt, the young MBA graduate who founded Proper Cloth. “It’s useful to us and lets our customers feel connected to Proper Cloth.” Rebecca Knight, “Custom-made for E-tail Success,” Financial Times, March 18, 2009, 10. Skerritt also writes a blog for the company. Twitter and podcasts that can be downloaded from iTunes are two other ways companies are amplifying the “word of mouth” about their products. Rebecca Knight, “Custom-made for E-tail Success,” Financial Times, March 18, 2009, 10. 3.1 The Consumer’s Decision-Making Process Learning Objectives Understand what the stages of the buying process are. Distinguish between low-involvement buying decisions and high-involvement buying decisions. You’ve been a consumer with purchasing power for much longer than you probably realize—since the first time you were asked which cereal or toy you wanted. Over the years, you’ve developed a systematic way you choose among alternatives, even if you aren’t aware of it. Other consumers follow a similar process. The first part of this chapter looks at this process. The second part looks at the situational, psychological, and other factors that affect what, when, and how people buy what they do. Keep in mind, however, that different people, no matter how similar they are, make different purchasing decisions. You might be very interested in purchasing a Smart Car. But your best friend might want to buy a Ford 150 truck. Marketing professionals understand this. They don’t have unlimited budgets that allow them to advertise in all types of media to all types of people, so what they try to do is figure out trends among consumers. Doing so helps them reach the people most likely to buy their products in the most cost effective way possible. Stages in the Buying Process Figure 3.2 "Stages in the Consumer’s Purchasing Process" outlines the buying stages consumers go through. At any given time, you’re probably in some sort of buying stage. You’re thinking about the different types of things you want or need to eventually buy, how you are going to find the best ones at the best price, and where and how will you buy them. Meanwhile, there are other products you have already purchased that you’re evaluating. Some might be better than others. Will you discard them, and if so, how? Then what will you buy? Where does that process start? Figure 3.2 Stages in the Consumer’s Purchasing Process Stage 1. Need Recognition Perhaps you’re planning to backpack around the country after you graduate, but you don’t have a particularly good backpack. Marketers often try to stimulate consumers into realizing they have a need for a product. Do you think it’s a coincidence that Gatorade, Powerade, and other beverage makers locate their machines in gymnasiums so you see them after a long, tiring workout? Previews at movie theaters are another example. How many times have you have heard about a movie and had no interest in it—until you saw the preview? Afterward, you felt like had to see it. Stage 2. Search for Information Maybe you have owned several backpacks and know what you like and don’t like about them. Or, there might be a particular brand that you’ve purchased in the past that you liked and want to purchase in the future. This is a great position for the company that owns the brand to be in—something firms strive for. Why? Because it often means you will limit your search and simply buy their brand again. If what you already know about backpacks doesn’t provide you with enough information, you’ll probably continue to gather information from various sources. Frequently people ask friends, family, and neighbors about their experiences with products. Magazines such as Consumer Reports or Backpacker Magazine might also help you. Internet shopping sites such as Amazon.com have become a common source of information about products. Epinions.com is an example of consumer-generated review site. The site offers product ratings, buying tips, and price information. Amazon.com also offers product reviews written by consumers. People prefer “independent” sources such as this when they are looking for product information. However, they also often consult nonneutral sources of information, such advertisements, brochures, company Web sites, and salespeople. Stage 3. Product Evaluation Obviously, there are hundreds of different backpacks available to choose from. It’s not possible for you to examine all of them. (In fact, good salespeople and marketing professionals know that providing you with too many choices can be so overwhelming, you might not buy anything at all.) Consequently, you develop what’s called evaluative criteria to help you narrow down your choices. Evaluative criteria Certain characteristics of products consumers consider when they are making buying decisions. are certain characteristics that are important to you such as the price of the backpack, the size, the number of compartments, and color. Some of these characteristics are more important than others. For example, the size of the backpack and the price might be more important to you than the color—unless, say, the color is hot pink and you hate pink. Figure 3.3 Osprey backpacks are known for their durability. The company has a special design and quality control center, and Osprey’s salespeople annually take a “canyon testing” trip to see how well the company’s products perform. © 2010 Jupiterimages Corporation Marketing professionals want to convince you that the evaluative criteria you are considering reflect the strengths of their products. For example, you might not have thought about the weight or durability of the backpack you want to buy. However, a backpack manufacturer such as Osprey might remind you through magazine ads, packaging information, and its Web site that you should pay attention to these features—features that happen to be key selling points of its backpacks. Stage 4. Product Choice and Purchase Stage 4 is the point at which you decide what backpack to purchase. However, in addition to the backpack, you are probably also making other decisions at this stage, including where and how to purchase the backpack and on what terms. Maybe the backpack was cheaper at one store than another, but the salesperson there was rude. Or maybe you decide to order online because you’re too busy to go to the mall. Other decisions, particularly those related to big ticket items, are made at this point. If you’re buying a high-definition television, you might look for a store that will offer you credit or a warranty. Stage 5. Postpurchase Use and Evaluation At this point in the process you decide whether the backpack you purchased is everything it was cracked up to be. Hopefully it is. If it’s not, you’re likely to suffer what’s called postpurchase dissonance A situation in which consumers rethink their decisions after purchasing products and wonder if they made the best decision. . You might call it buyer’s remorse. You want to feel good about your purchase, but you don’t. You begin to wonder whether you should have waited to get a better price, purchased something else, or gathered more information first. Consumers commonly feel this way, which is a problem for sellers. If you don’t feel good about what you’ve purchased from them, you might return the item and never purchase anything from them again. Or, worse yet, you might tell everyone you know how bad the product was. Companies do various things to try to prevent buyer’s remorse. For smaller items, they might offer a money back guarantee. Or, they might encourage their salespeople to tell you what a great purchase you made. How many times have you heard a salesperson say, “That outfit looks so great on you!”? For larger items, companies might offer a warranty, along with instruction booklets, and a toll-free troubleshooting line to call. Or they might have a salesperson call you to see if you need help with product. Stage 6. Disposal of the Product There was a time when neither manufacturers nor consumers thought much about how products got disposed of, so long as people bought them. But that’s changed. How products are being disposed is becoming extremely important to consumers and society in general. Computers and batteries, which leech chemicals into landfills, are a huge problem. Consumers don’t want to degrade the environment if they don’t have to, and companies are becoming more aware of the fact. Take for example, Crystal Light, a water-based beverage that’s sold in grocery stores. You can buy it in a bottle. However, many people buy a concentrated form of it, put it in reusable pitchers or bottles, and add water. That way, they don’t have to buy and dispose of plastic bottle after plastic bottle, damaging the environment in the process. Windex has done something similar with its window cleaner. Instead of buying new bottles of it all the time, you can purchase a concentrate and add water. You have probably noticed that most grocery stores now sell cloth bags consumers can reuse instead of continually using and discarding of new plastic or paper bags. Other companies are less concerned about conservation than they are about planned obsolescence A deliberate effort by companies to make their products obsolete, or unusable, after a period of time. . Planned obsolescence is a deliberate effort by companies to make their products obsolete, or unusable, after a period of time. The goal is to improve a company’s sales by reducing the amount of time between the repeat purchases consumers make of products. When a software developer introduces a new version of product, older versions of it are usually designed to be incompatible with it. For example, not all the formatting features are the same in Microsoft Word 2003 and 2007. Sometimes documents do not translate properly when opened in the newer version. Consequently, you will be more inclined to upgrade to the new version so you can open all Word documents you receive. Products that are disposable are another way in which firms have managed to reduce the amount of time between purchases. Disposable lighters are an example. Do you know anyone today that owns a nondisposable lighter? Believe it or not, prior to the 1960s, scarcely anyone could have imagined using a cheap disposable lighter. There are many more disposable products today than there were in years past—including everything from bottled water and individually wrapped snacks to single-use eye drops and cell phones. Figure 3.4 Disposable lighters came into vogue in the United States in the 1960s. You probably don’t own a cool, nondisposable lighter like one of these, but you don’t have to bother refilling it with lighter fluid either. © 2010 Jupiterimages Corporation Low-Involvement versus High-Involvement Buying Decisions Consumers don’t necessarily go through all the buying stages when they’re considering purchasing product. You have probably thought about many products you want or need but never did much more than that. At other times, you’ve probably looked at dozens of products, compared them, and then decided not to purchase any one of them. At yet other times, you skip stages 1 through 3 and buy products on impulse. As Nike would put, you “just do it.” Perhaps you see a magazine with Angelina Jolie and Brad Pitt on the cover and buy it on the spot simply because you want it. Purchasing a product with no planning or forethought is called impulse buying Purchases that occurs with no planning or forethought. . Impulse buying brings up a concept called level of involvement —that is, how personally important or interested you are in consuming a product. For example, you might see a roll of tape at a check-out stand and remember you need one. Or you might see a bag of chips and realize you’re hungry. These are items you need, but they are low-involvement products. Low-involvement products Products that carry a low risk of failure and/or have a low price tag for a specific individual or group making the decision. aren’t necessarily purchased on impulse, although they can be. Low-involvement products are, however, inexpensive and pose a low risk to the buyer if she makes a mistake by purchasing them. Consumers often engage in routine response behavior When consumers make automatic purchase decisions based on limited information or information they have gathered in the past. when they buy low-involvement products—that is, they make automatic purchase decisions based on limited information or information they have gathered in the past. For example, if you always order a Diet Coke at lunch, you’re engaging in routine response behavior. You may not even think about other drink options at lunch because your routine is to order a Diet Coke, and you simply do it. If you’re served a Diet Coke at lunchtime, and it’s flat, oh well. It’s not the end of the world. By contrast, high-involvement products Products that carry a high price tag or high level of risk to the individual or group making the decision. carry a high risk to buyers if they fail, are complex, or have high price tags. A car, a house, and an insurance policy are examples. These items are not purchased often. Buyers don’t engage in routine response behavior when purchasing high-involvement products. Instead, consumers engage in what’s called extended problem solving Purchasing decisions in which a consumer gathers a significant amount of information before making a decision. , where they spend a lot of time comparing the features of the products, prices, warrantees, and so forth. High-involvement products can cause buyers a great deal of postpurchase dissonance if they are unsure about their purchases. Companies that sell high-involvement products are aware of that postpurchase dissonance can be a problem. Frequently, they try to offer consumers a lot of information about their products, including why they are superior to competing brands and how they won’t let the consumer down. Salespeople are typically utilized to do a lot of customer “hand-holding.” Figure 3.5 Allstate’s “You’re in Good Hands” advertisements are designed to convince consumers that the insurance company won’t let them down. © 2010 Jupiterimages Corporation Limited problem solving falls somewhere in the middle. Consumers engage in limited problem solving Purchasing decisions made based on consideration of some outside information. when they already have some information about a good or service but continue to search for a bit more information. The backpack you’re looking to buy is an example. You’re going to spend at least some time looking for one that’s decent because you don’t want it to fall apart while you’re traveling and dump everything you’ve packed on a hiking trail. You might do a little research online and come to a decision relatively quickly. You might consider the choices available at your favorite retail outlet but not look at every backpack at every outlet before making a decision. Or, you might rely on the advice of a person you know who’s knowledgeable about backpacks. In some way you shorten the decision-making process. Brand names can be very important regardless of the consumer’s level of purchasing involvement. Consider a low- versus high-involvement product—say, purchasing a tube of toothpaste versus a new car. You might routinely buy your favorite brand of toothpaste, not thinking much about the purchase (engage in routine response behavior), but not be willing to switch to another brand either. Having a brand you like saves you “search time” and eliminates the evaluation period because you know what you’re getting. When it comes to the car, you might engage in extensive problem solving but, again, only be willing to consider a certain brands or brands. For example, in the 1970s, American-made cars had such a poor reputation for quality, buyers joked that a car that’s “not Jap [Japanese made] is crap.” The quality of American cars is very good today, but you get the picture. If it’s a high-involvement product you’re purchasing, a good brand name is probably going to be very important to you. That’s why the makers of high-involvement products can’t become complacent about the value of their brands. Video Clip 1970s American Cars (click to see video) Today, Lexus is the automotive brand that experiences the most customer loyalty. For a humorous, tongue-in-cheek look at why the brand reputation of American carmakers suffered in the 1970s, check out this clip. Key Takeaway Consumer behavior looks at the many reasons why people buy things and later dispose of them. Consumers go through distinct buying phases when they purchases products: (1) realizing the need or want something, (2) searching for information about the item, (3) evaluating different products, (4) choosing a product and purchasing it, (5) using and evaluating the product after the purchase, and (6) disposing of the product. A consumer’s level of involvement is how interested he or she is in buying and consuming a product. Low-involvement products are usually inexpensive and pose a low risk to the buyer if she makes a mistake by purchasing them. High-involvement products carry a high risk to the buyer if they fail, are complex, or have high price tags. Limited-involvement products fall somewhere in between. Review Questions What is consumer behavior? Why do companies study it? What stages do people go through in the buying process? How do low-involvement products differ from high-involvement products in terms of the risks their buyers face? Name some products in each category that you’ve recently purchased. 3.2 Situational Factors That Affect People’s Buying Behavior Learning Objectives Describe the situational factors that affect what consumers buy and when. Explain what marketing professionals can do to make situational factors work to their advantage. Situational influences are temporary conditions that affect how buyers behave—whether they actually buy your product, buy additional products, or buy nothing at all from you. They include things like physical factors, social factors, time factors, the reason for the buyer’s purchase, and the buyer’s mood. You have undoubtedly been affected by all these factors at one time or another. Because businesses very much want to try to control these factors, let’s now look at them in more detail. The Consumer’s Physical Situation Have you ever been in a department story and couldn’t find your way out? No, you aren’t necessarily directionally challenged. Marketing professionals take physical factors such as a store’s design and layout into account when they are designing their facilities. Presumably, the longer you wander around a facility, the more you will spend. Grocery stores frequently place bread and milk products on the opposite ends of the stores because people often need both types of products. To buy both, they have to walk around an entire store, which of course, is loaded with other items they might see and purchase. Store locations are another example of a physical factor. Starbucks has done a good job in terms of locating its stores. It has the process down to a science; you can scarcely drive a few miles down the road without passing a Starbucks. You can also buy cups of Starbucks coffee at many grocery stores and in airports—virtually any place where there is foot traffic. Physical factors like these—the ones over which firms have control—are called atmospherics The physical aspects of the selling environment retailers try to control. . In addition to store locations, they include the music played at stores, the lighting, temperature, and even the smells you experience. Perhaps you’ve visited the office of an apartment complex and noticed how great it looked and even smelled. It’s no coincidence. The managers of the complex were trying to get you to stay for a while and have a look at their facilities. Research shows that “strategic fragrancing” results in customers staying in stores longer, buying more, and leaving with better impression of the quality of stores’ services and products. Mirrors near hotel elevators are another example. Hotel operators have found that when people are busy looking at themselves in the mirrors, they don’t feel like they are waiting as long for their elevators. Patricia Moore, “Smells Sell,” NZ Business, February 2008, 26–27. Not all physical factors are under a company’s control, however. Take weather, for example. Rain and other types of weather can be a boon to some companies, like umbrella makers such as London Fog, but a problem for others. Beach resorts, outdoor concert venues, and golf courses suffer when the weather is rainy. So do a lot of retail organizations—restaurants, clothing stores, and automobile dealers. Who wants to shop for a car in the rain or snow? Firms often attempt to deal with adverse physical factors such as bad weather by making their products more attractive during unattractive times. For example, many resorts offer consumers discounts to travel to beach locations during hurricane season. Having an online presence is another way to cope with weather-related problems. What could be more comfortable than shopping at home? If it’s too cold and windy to drive to the GAP, REI, or Abercrombie & Fitch, you can buy these companies’ products online. You can shop online for cars, too, and many restaurants take orders online and deliver. Crowding is another situational factor. Have you ever left a store and not purchased anything because it was just too crowded? Some studies have shown that consumers feel better about retailers who attempt to prevent overcrowding in their stores. However, other studies have shown that to a certain extent, crowding can have a positive impact on a person’s buying experience. The phenomenon is often referred to as “herd behavior.” If people are lined up to buy something, you want to know why. Should you get in line to buy it too? Herd behavior helped drive up the price of houses in the mid-2000s before the prices for them rapidly fell. Unfortunately, herd behavior has also led to the deaths of people. In 2008, a store employee was trampled to death by an early morning crowd rushing into a Walmart to snap up holiday bargains. To some extent, how people react to crowding depends on their personal tolerance levels. Which rock concert would you rather attend: A sold-out concert in which the crowd is having a rocking good time? Or a half-sold-out concert where you can perhaps move to a seat closer to the stage and not have to stand in line at the restrooms? Carol J. Gaumer and William C. Leif, “Social Facilitation: Affect and Application in Consumer Buying Situations,” Journal of Food Products Marketing 11, no. 1 (2005): 75–82. The Consumer’s Social Situation The social situation you’re in can significantly affect what you will buy, how much of it, and when. Perhaps you have seen Girl Scouts selling cookies outside grocery stores and other retail establishments and purchased nothing from them. But what if your neighbor’s daughter is selling the cookies? Are you going to turn her down, or be a friendly neighbor and buy a box (or two)? Video Clip Thin Mints, Anyone? (click to see video) Are you going to turn down this cute Girl Scout’s cookies? What if she’s your neighbor’s daughter? Pass the milk, please! Companies like Avon and Tupperware that sell their products at parties understand that the social situation you’re in makes a difference. When you’re at a Tupperware party a friend is having, you don’t want to disappoint her by not buying anything. Plus, everyone at the party will think you’re cheap. Certain social situations can also make you less willing to buy products. You might spend quite a bit of money each month eating at fast-food restaurants like McDonald’s and Subway. But suppose you’ve got a hot first date? Where do you take your date? Some people might take a first date to Subway, but that first date might also be the last. Other people would perhaps choose a restaurant that’s more upscale. Likewise, if you have turned down a drink or dessert on a date because you were worried about what the person you were with might have thought, your consumption was affected by your social situation. Anna S. Matilla and Jochen Wirtz, “The Role of Store Environmental Stimulation and Social Factors on Impulse Purchasing,” Journal of Services Marketing 22, no. 7 (2008): 562–67. The Consumer’s Time Situation The time of day, the time of year, and how much time consumers feel like they have to shop also affects what they buy. Researchers have even discovered whether someone is a “morning person” or “evening person” affects shopping patterns. Seven-Eleven Japan is a company that’s extremely in tune to physical factors such as time and how it affects buyers. The company’s point-of-sale systems at its checkout counters monitor what is selling well and when, and stores are restocked with those items immediately—sometimes via motorcycle deliveries that zip in and out of traffic along Japan’s crowded streets. The goal is to get the products on the shelves when and where consumers want them. Seven-Eleven Japan also knows that, like Americans, its customers are “time starved.” Shoppers can pay their utility bills, local taxes, and insurance or pension premiums at Seven-Eleven Japan stores, and even make photocopies. Allan Bird, “Retail Industry,” Encyclopedia of Japanese Business and Management (London: Routledge, 2002), 399–400. Companies worldwide are aware of people’s lack of time and are finding ways to accommodate them. Some doctors’ offices offer drive-through shots for patients who are in a hurry and for elderly patients who find it difficult to get out of their cars. Tickets.com allows companies to sell tickets by sending them to customers’ mobile phones when they call in. The phones’ displays are then read by barcode scanners when the ticket purchasers arrive at the events they’re attending. Likewise, if you need customer service from Amazon.com, there’s no need to wait on hold on the telephone. If you have an account with Amazon, you just click a button on the company’s Web site and an Amazon representative calls you immediately. The Reason for the Consumer’s Purchase The reason you are shopping also affects the amount of time you will spend shopping. Are you making an emergency purchase? Are you shopping for a gift? In recent years, emergency clinics have sprung up in strip malls all over the country. Convenience is one reason. The other is sheer necessity. If you cut yourself and you are bleeding badly, you’re probably not going to shop around much to find the best clinic to go to. You will go to the one that’s closest to you. What about shopping for a gift? Purchasing a gift might not be an emergency situation, but you might not want to spend much time shopping for it either. Gift certificates have been a popular way to purchase for years. But now you can purchase them as cards at your corner grocery store. By contrast, suppose you need to buy an engagement ring. Sure, you could buy one online in a jiffy, but you probably wouldn’t, because it’s a high-involvement product. What if it were a fake? How would you know until after you purchased it? What if your significant other turned you down and you had to return the ring? How hard would it be to get back online and return the ring? Jacob Hornik and Giulia Miniero, “Synchrony Effects on Customers’ Responses and Behaviors,” International Journal of Research in Marketing 26, no. 1 (2009): 34–40. The Consumer’s Mood Have you ever felt like going on a shopping spree? At other times wild horses couldn’t drag you to a mall. People’s moods temporarily affect their spending patterns. Some people enjoy shopping. It’s entertaining for them. At the extreme are compulsive spenders who get a temporary “high” from spending. A sour mood can spoil a consumer’s desire to shop. The crash of the U.S. stock market in 2008 left many people feeling poorer, leading to a dramatic downturn in consumer spending. Penny pinching came into vogue, and conspicuous spending was out. Costco and Walmart experienced heightened sales of their low-cost Kirkland Signature and Great Value brands as consumers scrimped. “Wal-Mart Unveils Plans for Own-Label Revamp,” Financial Times, March 17, 2009, 15. Saks Fifth Avenue wasn’t so lucky. Its annual release of spring fashions usually leads to a feeding frenzy among shoppers, but spring 2009 was different. “We’ve definitely seen a drop-off of this idea of shopping for entertainment,” says Kimberly Grabel, Saks Fifth Avenue’s senior vice president of marketing. Stephanie Rosenbloom (New York Times News Service), “Where Have All the Shoppers Gone?” Fort Worth Star-Telegram, March 18, 2009, 5E. To get buyers in the shopping mood, companies resorted to different measures. The upscale retailer Neiman Marcus began introducing more midpriced brands. By studying customer’s loyalty cards, the French hypermarket Carrefour hoped to find ways to get its customers to purchase nonfood items that have higher profit margins. The glum mood wasn’t bad for all businesses though. Discounters like Half-Priced books saw their sales surge. So did seed sellers as people began planting their own gardens. Finally, those products you see being hawked on television? Aqua Globes, Snuggies, and Ped Eggs? Their sales were the best ever. Apparently, consumers too broke to go to on vacation or shop at Saks were instead watching television and treating themselves to the products. Alyson Ward, “Products of Our Time,” Fort Worth Star-Telegram, March 7, 2009, 1E. Key Takeaway Situational influences are temporary conditions that affect how buyers behave. They include physical factors such as a store’s buying locations, layout, music, lighting, and even smells. Companies try to make the physical factors in which consumers shop as favorable as possible. If they can’t, they utilize other tactics such as discounts. The consumer’s social situation, time situation, the reason for their purchases, and their moods also affect their buying behavior. Review Questions Why and how does the social situation the consumer is in play a role in behavior? Outline the types of physical factors companies try to affect and how they go about it. What social situations have you been in that affected what you purchased? What types of moods and time situations are likely to affect people’s buying behavior? 3.3 Personal Factors That Affect People’s Buying Behavior Learning Objectives Explain how a person’s self-concept and ideal self affects what he or she buys. Describe how companies market products to people based on their genders, life stages, and ages. Explain how looking at the lifestyles of consumers helps firms understand what they want to purchase. The Consumer’s Personality Personality An individual’s disposition as other people see it. describes a person’s disposition as other people see it. The following are the “Big Five” personality traits that psychologists discuss frequently: Openness. How open you are to new experiences. Conscientiousness. How diligent you are. Extraversion. How outgoing or shy you are. Agreeableness. How easy you are to get along with. Neuroticism. How prone you are to negative mental states. The question marketing professionals want answered is do the traits predict people’s purchasing behavior? Can companies successfully target certain products at people based on their personalities? And how do you find out what personalities they have? Are the extraverts you know wild spenders and the introverts you know penny pinchers? Maybe not. The link between people’s personalities and their buying behavior is somewhat unclear, but market researchers continue to study it. For example, some studies have shown that “sensation seekers,” or people who exhibit extremely high levels of openness, are more likely to respond well to advertising that’s violent and graphic. The practical problem for firms is figuring out “who’s who” in terms of their personalities. The Consumer’s Self-Concept Marketers have had better luck linking people’s self-concept to their buying behavior. Your self-concept How a person sees himself or herself. is how you see yourself—be it positive or negative. Your ideal self How a person would like to view himself or herself. is how you would like to see yourself—whether it’s prettier, more popular, more eco-conscious, or more “goth.” Marketing researchers believe people buy products to enhance how they feel about themselves—to get themselves closer to their ideal selves, in other words. The slogan “Be All That You Can Be,” which for years was used by the U.S. Army to recruit soldiers, is an attempt to appeal to the self-concept. Presumably, by joining the U.S. Army, you will become a better version of yourself, which will, in turn, improve your life. Many beauty products and cosmetic procedures are advertised in a way that’s supposed to appeal to the ideal selves people are searching for. All of us want products that improve our lives. The Consumer’s Gender Everyone knows that men and women buy different products. Physiologically speaking, they simply need different product—different underwear, shoes, toiletries, and a host of other products. Cheryl B. Ward and Tran Thuhang, “Consumer Gifting Behaviors: One for You, One for Me?” Services Marketing Quarterly 29, no. 2 (2007): 1–17. Men and women also shop differently. One study by Resource Interactive, a technology research firm, found that when shopping online, men prefer sites with lots of pictures of products; women prefer to see products online in lifestyle context—say, a lamp in a living room. Women are also twice as likely as men to use viewing tools such as the zoom and rotate buttons and links that allow them to change the color of products. In general, men have a different attitude about shopping than women do. You know the old stereotypes: Men see what they a want and buy it, but women “shop ‘til they drop.” There’s some truth to the stereotypes. Otherwise, you wouldn’t see so many advertisements directed at one sex or the other—beer commercials that air on ESPN and commercials for household products that air on Lifetime. In fact, women influence fully two-thirds of all household product purchases, whereas men buy about three-quarters of all alcoholic beverages. Genevieve Schmitt, “Hunters and Gatherers,” Dealernews 44, no. 8 (2008): 72. The article references the 2006 Behavioral Tracking Study by Miller Brewing Company. Video Clip What Women Want versus What Men Want (click to see video) Check out this Heineken commercial which highlights the differences between “what women want” and “what men want” when it comes to products. The shopping differences between men and women seem to be changing, though. For example, younger, well-educated men are less likely to believe grocery shopping is a woman’s job. They would also be more inclined to bargain shop and use coupons if the coupons were properly targeted at them. Jeanne Hill and Susan K. Harmon, “Male Gender Role Beliefs, Coupon Use and Bargain Hunting,” Academy of Marketing Studies Journal 11, no. 2 (2007): 107–21. One survey found that approximately 45 percent of married men actually like shopping and consider it relaxing. Figure 3.6 Marketing to men is big business. Some advertising agencies specialize in advertisements designed specifically to appeal to male consumers. © 2010 Jupiterimages Corporation Many businesses today are taking greater pains to figure out “what men want.” Products such as face toners and body washes for men, such as the Axe brand, are a relatively new phenomenon. So are hair salons such as the Men’s Zone and Weldon Barber. Some advertising agencies specialize in advertising directed at men. Keep in mind that there are also many items targeted toward women that weren’t in the past, including products such as kayaks and mountain bikes. The Consumer’s Age and Stage of Life You have probably noticed that the things you buy have changed as you age. When you were a child, the last thing you probably wanted as a gift was clothing. As you became a teen, however, cool clothes probably became a bigger priority. Don’t look now, but depending on the stage of life you’re currently in, diapers and wrinkle cream might be just around the corner. Companies understand that people buy different things based on their ages and life stages. Aging baby boomers are a huge market that companies are trying to tap. Ford and other car companies have created “aging suits” for young employees to wear when they’re designing automobiles. “Designing Cars for the Elderly: A Design Story,” http://www.businessweek.com/globalbiz/content/may2008/gb2008056_154197.htm (accessed April 13, 2012). The suit simulates the restricted mobility and vision people experience as they get older. Car designers can then figure out how to configure the automobiles to better meet the needs of these consumers. Lisa Rudes Sandel, the founder of Not Your Daughter’s Jeans (NYDJ), created a multimillion-dollar business by designing jeans for baby boomers with womanly bodies. Since its launch seven years ago, NYDJ has become the largest domestic manufacturer of women’s jeans under $100. “The truth is,” Rudes Sandel says, “I’ve never forgotten that woman I’ve been aiming for since day one.” Sandel “speaks to” every one of her customers via a note tucked into each pair of jean that reads, “NYDJ (Not Your Daughter’s Jeans) cannot be held responsible for any positive consequence that may arise due to your fabulous appearance when wearing the Tummy Tuck jeans. You can thank me later.” Sarah Saffian, “Dreamers: The Making of Not Your Daughter’s Jeans,” Reader’s Digest, March 2009, 53–55. Figure 3.7 You’re only as old as you feel—and the things you buy. © 2010 Jupiterimages Corporation Your chronological age A person’s age in years. , or actual age in years, is one thing. Your cognitive age The age a buyer perceives himself or herself to be. , or how old you perceive yourself to be, is another. In other words, how old do you really feel? A person’s cognitive age affects the activities one engages in and sparks interests consistent with the person’s perceived age. Benny Barak and Steven Gould, “Alternative Age Measures: A Research Agenda,” in Advances in Consumer Research, vol. 12, ed. Elizabeth C. Hirschman and Morris B. Holbrook (Provo, UT: Association for Consumer Research, 1985), 53–58. Cognitive age is a significant predictor of consumer behaviors, including people’s dining out, watching television, going to bars and dance clubs, playing computer games, and shopping. Benny Barak and Steven Gould, “Alternative Age Measures: A Research Agenda,” in Advances in Consumer Research, vol. 12, ed. Elizabeth C. Hirschman and Morris B. Holbrook (Provo, UT: Association for Consumer Research, 1985), 53–58. How old people “feel” they are has important implications for marketing professionals. For example, companies have found that many “aged” consumers don’t take kindly to products that feature “old folks.” The consumers can’t identify with them because they see themselves as being younger. We will discuss more about the various age groups and how marketing professionals try to target them in Chapter 5 "Market Segmenting, Targeting, and Positioning". The Consumer’s Lifestyle At the beginning of the chapter, we explained that two consumers (say, you and your best friend) can be similar in age, personality, gender, and so on but still purchase very different products. If you have ever watched the television show Wife Swap, you can see that despite people’s similarities (e.g., being middle-class Americans who are married with children), their lifestyles can differ radically. To better understand consumers and connect with them, companies have begun looking more closely at consumers’ lifestyles. This often includes asking consumers to fill out extensive questionnaires or conducting in-depth interviews with them. The questionnaires go beyond asking people about the products they like, where they live, and what sex they are. Instead, researchers ask people what they do —that is, how they spend their time and what their priorities, values, and general outlooks on the world are. Where do they go other than work? Who do they like to talk to? What do they talk about? Researchers hired by Procter & Gamble have gone so far as to follow women around for weeks as they shop, run errands, and socialize with one another. Robert Berner, “Detergent Can Be So Much More,” BusinessWeek, May 1, 2006, 66–68. Other companies have paid people to keep a daily journal of their activities and routines. Audio Clip Interview with Joy Mead http://app.wistia.com/embed/medias/45f9c7fa67 Joy Mead is an associate director of marketing for Procter & Gamble. Listen to this audio clip to learn about the approach Procter & Gamble takes to understand customers. A number of research organizations examine lifestyle and psychographic characteristics of consumers. Psychographics Measuring the attitudes, values, lifestyles, and opinions of consumers using demographics. combines the lifestyle traits of consumers (for example, whether they are single or married, wealthy or poor, well-educated or high school dropouts) and their personality styles with an analysis of their attitudes, activities, and values to determine groups of consumers with similar characteristics. We will talk more about psychographics and what companies do to develop further insight into what consumers want in Chapter 5 "Market Segmenting, Targeting, and Positioning". Key Takeaway Your personality describes your disposition as other people see it. Market researchers believe people buy products to enhance how they feel about themselves. Your gender also affects what you buy and how you shop. Women shop differently than men. However, there’s some evidence that this is changing. Younger men and women are beginning to shop more alike. People buy different things based on their ages and life stages. A person’s cognitive age is how old he “feels” himself to be. To further understand consumers and connect with them, companies have begun looking more closely at their lifestyles (what they do, how they spend their time, what their priorities and values are, and how they see the world). Review Questions Explain how someone’s personality differs from his or her self-concept. How does the person’s ideal self come into play in a consumer-behavior context? Describe the buying patterns women exhibit versus men. Why are companies interested in consumers’ cognitive ages? What are some of the consumer lifestyle factors firms examine? 3.4 Psychological Factors That Affect People’s Buying Behavior Learning Objectives Explain how Maslow’s hierarchy of needs works. Outline the additional psychological factors that affect people’s buying behavior. Motivation Motivation The inward drive people have to get what they need. is the inward drive we have to get what we need. In the mid-1900s, Abraham Maslow, an American psychologist, developed the hierarchy of needs shown in Figure 3.8 "Maslow’s Hierarchy of Needs". Figure 3.8 Maslow’s Hierarchy of Needs Maslow theorized that people have to fulfill their basic needs—like the need for food, water, and sleep—before they can begin fulfilling higher-level needs. Have you ever gone shopping when you were tired or hungry? Even if you were shopping for something that would make you envy of your friends (maybe a new car) you probably wanted to sleep or eat even worse. (Forget the car. Just give me a nap and a candy bar.) People’s needs can be recurring, such as the physiological need for hunger. You eat breakfast and are hungry at lunchtime and then again in the evening. Other needs tend to be enduring, such as the need for shelter, clothing, and safety. Still other needs arise at different points in time in a person’s life. For example, during grade school and high school, your social needs probably rose to the forefront. You wanted to have friends and get a date. Perhaps this prompted you to buy certain types of clothing or electronic devices. After high school, you began thinking about how people would view you in your “station” in life, so you decided to pay for college and get a professional degree, thereby fulfilling your need for esteem. If you’re lucky, at some point you will realize Maslow’s state of self-actualization: You will believe you have become the person in life that you feel you were meant to be. Marketing professionals understand Maslow’s hierarchy. Take the need for people to feel secure and safe. Following the economic crisis that began in 2008, the sales of new automobiles dropped sharply virtually everywhere around the world—except the sales of Hyundai vehicles. Hyundai ran an ad campaign that assured car buyers they could return their vehicles if they couldn’t make the payments on them without damaging their credit. Other carmakers began offering similar programs after they saw how successful Hyundai had been. Likewise, banks began offering “worry-free” mortgages to ease the minds of would-be homebuyers. For a fee of about $500, First Mortgage Corp., a Texas-based bank, offered to make a homeowner’s mortgage payment for six months if he or she got laid off. Andrea Jares, “New Programs Are Taking Worries from Home Buying,” Fort Worth Star-Telegram, March 7, 2010, 1C–2C. The Consumer’s Perception Perception How people interpret the world around them. is how you interpret the world around you and make sense of it in your brain. You do so via stimuli that affect your different senses—sight, hearing, touch, smell, and taste. How you combine these senses also makes a difference. For example, in one study, consumers were blindfolded and asked to drink a new brand of clear beer. Most of them said the product tasted like regular beer. However, when the blindfolds came off and they drank the beer, many of them described it as “watery” tasting. Laura Ries, In the Boardroom: Why Left-Brained Management and Right-Brain Marketing Don’t See Eye-to-Eye (New York: HarperCollins, 2009). Using different types of stimuli, marketing professionals try to make you more perceptive to their products whether you need them or not. It’s not an easy job. Consumers today are bombarded with all types of marketing from every angle—television, radio, magazines, the Internet, and even bathroom walls. It’s been estimated that the average consumer is exposed to about three thousand advertisements per day. Kalle Lasn, Culture Jam: The Uncooling of America (New York: William Morrow & Company, 1999). Consumers are also multitasking more today than in the past. They are surfing the Internet, watching television, and checking their cell phones for text messages simultaneously. All day, every day, we are receiving information. Some, but not all, of it makes it into our brains. Have you ever read or thought about something and then started noticing ads and information about it popping up everywhere? That’s because your perception of it had become heightened. Many people are more perceptive to advertisements for products they need. Selective perception The process whereby a person filters information based on how relevant it is to them. is the process of filtering out information based on how relevant it is to you. It’s been described as a “suit of armor” that helps you filter out information you don’t need. At other times, people forget information, even if it’s quite relevant to them, which is called selective retention The process whereby a person retains information based on how well it matches their values and beliefs. . Usually the information contradicts the person’s belief. A longtime chain smoker who forgets much of the information communicated during an antismoking commercial is an example. To be sure their advertising messages get through to you, companies use repetition. How tired of iPhone commercials were you before they tapered off the tube? How often do you see the same commercial aired during a single television show? Video Clip A Parody of an iPhone Commercial (click to see video) Check out this parody on Apple’s iPhone commercial. Using surprising stimuli is also a technique. Sometimes this is called shock advertising Advertising designed to startle people so as to get their attention. . The clothing makers Benetton and Calvin Klein are probably best known for their shocking advertising. Calvin Klein sparked an uproar when it featured scantily clad prepubescent teens in its ads. There’s evidence that shock advertising actually works, though. One study found that shocking content increased attention, benefited memory, and positively influenced behavior among a group of university students. Darren W. Dahl, Kristina D. Frankenberger, and Rajesh V. Manchanda, “Does It Pay to Shock? Reactions to Shocking and Nonshocking Advertising Content among University Students,” Journal of Advertising Research 43, no. 3 (2003): 268–80. Subliminal advertising Advertising that is not apparent to consumers but is thought to be perceived subconsciously by them. is the opposite of shock advertising. It involves exposing consumers to marketing stimuli—photos, ads, message, and so forth—by stealthily embedding them in movies, ads, and other media. For example, the words Drink Coca-Cola might be flashed for a millisecond on a movie screen. Consumers were thought to perceive the information subconsciously, and it would make them buy products. Keep in mind that today it’s common to see brands such as Coke being consumed in movies and television programs, but there’s nothing subliminal about it. Coke and other companies often pay to have their products in the shows. The general public became aware of subliminal advertising in the 1960s. Many people considered the practice to be subversive, and in 1974, the Federal Communications Commission condemned it. Its effectiveness is somewhat sketchy, in any case. It didn’t help that much of the original research on it, conducted in the 1950s by a market researcher who was trying to drum up business for his market research firm, was fabricated. Cynthia Crossen, “For a Time in the ’50s, A Huckster Fanned Fears of Ad ‘Hypnosis,’” Wall Street Journal, November 5, 2007, eastern edition, B1. People are still fascinated by subliminal advertising, however. To create “buzz” about the television show The Mole in 2008, ABC began hyping it by airing short commercials composed of just a few frames. If you blinked, you missed it. Some television stations actually called ABC to figure out what was going on. One-second ads were later rolled out to movie theaters. Josef Adalian, “ABC Hopes ‘Mole’ Isn’t Just a Blip,” Television Week, June 2, 2008, 3. Even if your marketing effort reaches consumers and they retain it, different consumers can perceive it differently. Show two people the same product and you’ll get two different perceptions of it. One man sees Pledge, an outstanding furniture polish, while another sees a can of spray no different from any other furniture polish. One woman sees a luxurious Gucci purse, and the other sees an overpriced bag to hold keys and makeup. James Chartrand, “Why Targeting Selective Perception Captures Immediate Attention,” http://www.copyblogger.com/selective-perception (accessed October 14, 2009). A couple of frames about The Mole might make you want to see the television show. However, your friend might see the ad, find it stupid, and never tune in to watch the show. Learning Learning The process by which consumers change their behavior after they gain information or experience with a product. refers to the process by which consumers change their behavior after they gain information or experience a product. It’s the reason you don’t buy a crummy product twice. Learning doesn’t just affect what you buy, however. It affects how you shop. People with limited experience about a product or brand generally seek out more information about it than people who have used it before. Companies try to get consumers to learn about their products in different ways. Car dealerships offer test drives. Pharmaceutical reps leave behind lots of free items at doctor’s offices with medication names and logos written all over them—pens, coffee cups, magnets, and so on. Free samples of products that come in the mail or are delivered with newspapers are another example. To promote its new line of coffees, McDonald’s offered customers free samples to try. Another kind of learning is operant conditioning A type of behavior that’s repeated when it’s rewarded. , which is what occurs when researchers are able to get a mouse to run through a maze for a piece cheese or a dog to salivate just by ringing a bell. Companies engage in operant conditioning by rewarding consumers, too. The prizes that come in Cracker Jacks and with McDonald’s Happy Meals are examples. The rewards cause consumers to want to repeat their purchasing behaviors. Other rewards include free tans offered with gym memberships, punch cards that give you a free Subway sandwich after a certain number of purchases, and free car washes when you fill up your car with a tank of gas. Consumer’s Attitude Attitudes “Mental positions” or emotional feelings people have about products, services, companies, ideas, issues, or institutions. are “mental positions” or emotional feelings people have about products, services, companies, ideas, issues, or institutions. “Dictionary of Marketing Terms,” http://www.allbusiness.com/glossaries/marketing/4941810-1.html (accessed October 14, 2009). Attitudes tend to be enduring, and because they are based on people’s values and beliefs, they are hard to change. That doesn’t stop sellers from trying, though. They want people to have positive rather than negative feelings about their offerings. A few years ago, KFC began running ads to the effect that fried chicken was healthy—until the U.S. Federal Trade Commission told the company to stop. Wendy’s slogan to the effect that its products are “way better than fast food” is another example. Fast food has a negative connotation, so Wendy’s is trying to get consumers to think about its offerings as being better. A good example of a shift in the attitudes of consumers relates to banks. The taxpayer-paid government bailouts of big banks that began in 2008 provoked the wrath of Americans, creating an opportunity for small banks not involved in the credit derivates and subprime mortgage mess. The Worthington National Bank, a small bank in Fort Worth, Texas, ran billboards reading: “Did Your Bank Take a Bailout? We didn’t.” Another read: “Just Say NO to Bailout Banks. Bank Responsibly!” The Worthington Bank received tens of millions in new deposits soon after running these campaigns. Joe Mantone, “Banking on TARP Stigma,” SNLi, March 16, 2009, http://www.snl.com/Interactivex/article.aspx?CdId=A-9218440-12642 (accessed October 14, 2009). Figure 3.9 Worthington National, a small Texas bank, capitalized on people’s bad attitudes toward big banks that accepted bailouts from the government in 2008–2009. After running billboards with this message, the bank received millions of dollars in new deposits. © WorthingtonBank.com Key Takeaway Psychologist Abraham Maslow theorized that people have to fulfill their basic needs—like the need for food, water, and sleep—before they can begin fulfilling higher-level needs. Perception is how you interpret the world around you and make sense of it in your brain. To be sure their advertising messages get through to you, companies often resort to repetition. Shocking advertising and subliminal advertising are two other methods. Learning is the process by which consumers change their behavior after they gain information about or experience with a product. Consumers’ attitudes are the “mental positions” people take based on their values and beliefs. Attitudes tend to be enduring and are often difficult for companies to change. Review Questions How does Maslow’s Hierarchy of Needs help marketing professionals? How does the process of perception work and how can companies use it to their advantage in their marketing? What types of learning do companies try to get consumers to engage in? 3.5 Societal Factors That Affect People’s Buying Behavior Learning Objectives Explain why the culture, subcultures, social classes, and families consumers belong to affect their buying behavior. Describe what reference groups and opinion leaders are. Situational factors—the weather, time of day, where you are, who you are with, and your mood—influence what you buy, but only on a temporary basis. So do personal factors, such as your gender, as well as psychological factors, such as your self-concept. Societal factors are a bit different. They are more outward. They depend on the world around you and how it works. The Consumer’s Culture Culture The shared beliefs, customs, behaviors, and attitudes that characterize a society used to cope with their world and with one another. refers to the shared beliefs, customs, behaviors, and attitudes that characterize a society. Your culture prescribes the way in which you should live. As a result, it has a huge effect on the things you purchase. For example, in Beirut, Lebanon, women can often be seen wearing miniskirts. If you’re a woman in Afghanistan wearing a miniskirt, however, you could face bodily harm or death. In Afghanistan women generally wear burqas, which cover them completely from head to toe. Similarly, in Saudi Arabia, women must wear what’s called an abaya, or long black garment. Interestingly, abayas have become big business in recent years. They come in many styles, cuts, and fabrics. Some are encrusted with jewels and cost thousands of dollars. To read about the fashions women in Muslim countries wear, check out the following article: http://www.time.com/time/world/article/0,8599,1210781,00.html. Even cultures that share many of the same values as the United States can be quite different from the United States in many ways. Following the meltdown of the financial markets in 2008, countries around the world were pressed by the United States to engage in deficit spending so as to stimulate the worldwide economy. But the plan was a hard sell both to German politicians and the German people in general. Most Germans don’t own credit cards, and running up a lot of debt is something people in that culture generally don’t do. Companies such as Visa and MasterCard and businesses that offer consumers credit to purchase items with high ticket prices have to deal with factors such as these. The Consumer’s Subculture (s) A subculture A group of people within a culture who are different from the dominant culture but have something in common with one another, such as common interests, vocations or jobs, religions, ethnic backgrounds, or sexual orientations. is a group of people within a culture who are different from the dominant culture but have something in common with one another—common interests, vocations or jobs, religions, ethnic backgrounds, sexual orientations, and so forth. The fastest-growing subculture in the United States consists of people of Hispanic origin, followed by Asian Americans, and blacks. The purchasing power of U.S. Hispanics is growing by leaps and bounds. By 2010 it is expected to reach more than $1 trillion. Larry Watrous, “Illegals: The New N-Word in America,” Fort Worth Star-Telegram, March 16, 2009, 9B. This is a lucrative market that companies are working to attract. Home Depot has launched a Spanish version of its Web site. Walmart is in the process of converting some of its Neighborhood Markets into stores designed to appeal to Hispanics. The Supermarcado de Walmart stores are located in Hispanic neighborhoods and feature elements such as cafés serving Latino pastries and coffee and full meat and fish counters. Jonathan Birchall, “Wal-Mart Looks to Hispanic Market in Expansion Drive,” Financial Times, March 13, 2009, 18. Figure 3.10 Care to join the subculture of the “Otherkin”? Otherkins are primarily Internet users who believe they are reincarnations of mythological or legendary creatures—angels, demons, vampires—you name it. To read more about the Otherkins and seven other bizarre subcultures, visit http://www.oddee.com/item_96676.aspx. © 2010 Jupiterimages Corporation Marketing products based the ethnicity of consumers is useful. However, it could become harder to do in the future because the boundaries between ethnic groups are blurring. For example, many people today view themselves as multiracial. (Golfer Tiger Woods is a notable example.) Also, keep in mind that ethnic and racial subcultures are not the only subcultures marketing professionals look at. As we have indicated, subcultures can develop in response to people’s interest. You have probably heard of the hip-hop subculture, people who in engage in extreme types of sports such as helicopter skiing, or people who play the fantasy game Dungeons and Dragons. The people in these groups have certain interests and exhibit certain behaviors that allow marketing professionals design specific products for them. The Consumer’s Social Class A social class A group of people who have the same social, economic, or educational status in society. is a group of people who have the same social, economic, or educational status in society. Princeton University, “WordNet,” http://wordnetweb.princeton.edu/perl/webwn?s=social+class&sub=Search+WordNet&o2=&o0=1&o7=&o5=&o1 =1&o6=&o4=&o3=&h= (accessed October 14, 2009). To some degree, consumers in the same social class exhibit similar purchasing behavior. Have you ever been surprised to find out that someone you knew who was wealthy drove a beat-up old car or wore old clothes and shoes? If so, it was because the person, given his or her social class, was behaving “out of the norm” in terms of what you thought his or her purchasing behavior should be. Table 3.1 "Social Classes and Buying Patterns: An Example" shows seven classes of American consumers along with the types of car brands they might buy. Keep in mind that the U.S. market is just a fraction of the world market. As we explained in Chapter 2 "Strategic Planning", to sustain their products, companies often launch their products in other parts of the world. The rise of the middle class in India and China is creating opportunities for many companies to successfully do this. For example, China has begun to overtake the United States as the world’s largest auto market. “More Cars Sold in China than in January,” France 24, February 10, 2009, http://www.france24.com/en/20090210-more-cars-sold-china-us-january-auto-market (accessed October 14, 2009). Table 3.1 Social Classes and Buying Patterns: An Example Class Type of Car Definition of Class Upper-Upper Class Rolls-Royce People with inherited wealth and aristocratic names (the Kennedys, Rothschilds, Windsors, etc.) Lower-Upper Class Mercedes Professionals such as CEOs, doctors, and lawyers Upper-Middle Class Lexus College graduates and managers Middle Class Toyota Both white-collar and blue-collar workers Working Class Pontiac Blue-collar workers Lower but Not the Lowest Used Vehicle People who are working but not on welfare Lowest Class No vehicle People on welfare The makers of upscale brands in particular walk a fine line in terms of marketing to customers. On the one hand, they want their customer bases to be as large as possible. This is especially tempting in a recession when luxury buyers are harder to come by. On the other hand, if the companies create products the middle class can better afford, they risk “cheapening” their brands. That’s why, for example, Smart Cars, which are made by BMW, don’t have the BMW label on them. For a time, Tiffany’s sold a cheaper line of silver jewelry to a lot of customers. However, the company later worried that its reputation was being tarnished by the line. Keep in mind that a product’s price is to some extent determined by supply and demand. Luxury brands therefore try to keep the supply of their products in check so their prices remain high. Figure 3.11 The whiskey brand Johnnie Walker has managed to expand its market share without cheapening the brand by producing a few lower-priced versions of the whiskey and putting them in bottles with different labels. © 2010 Jupiterimages Corporation Some companies have managed to capture market share by introducing “lower echelon” brands without damaging their luxury brands. Johnnie Walker is an example. The company’s whiskeys come in bottles with red, green, blue, black, and gold labels. The blue label is the company’s best product. Every blue-label bottle has a serial number and is sold in a silk-lined box, accompanied by a certificate of authenticity. “Johnnie Walker,” http://en.wikipedia.org/wiki/Johnnie_Walker (accessed October 14, 2009). Reference Groups and Opinion Leaders Of course, you probably know people who aren’t wealthy but who still drive a Mercedes or other upscale vehicle. That’s because consumers have reference groups. Reference groups Groups a consumer identifies with and wants to join. are groups a consumer identifies with and wants to join. If you have ever dreamed of being a professional player of basketball or another sport, you have a reference group. Marketing professionals are aware of this. That’s why, for example, Nike hires celebrities such as Michael Jordan to pitch the company’s products. Opinion leaders People with expertise certain areas. Consumers respect these people and often ask their opinions before they buy goods and services. are people with expertise in certain areas. Consumers respect these people and often ask their opinions before they buy goods and services. An information technology specialist with a great deal of knowledge about computer brands is an example. These people’s purchases often lie at the forefront of leading trends. For example, the IT specialist we mentioned is probably a person who has the latest and greatest tech products, and his opinion of them is likely to carry more weight with you than any sort of advertisement. Today’s companies are using different techniques to reach opinion leaders. Network analysis using special software is one way of doing so. Orgnet.com has developed software for this purpose. Orgnet’s software doesn’t mine sites like Facebook and LinkedIn, though. Instead, it’s based on sophisticated techniques that unearthed the links between Al Qaeda terrorists. Explains Valdis Krebs, the company’s founder: “Pharmaceutical firms want to identify who the key opinion leaders are. They don’t want to sell a new drug to everyone. They want to sell to the 60 key oncologists.” Anita Campbell, “Marketing to Opinion Leaders,” Small Business Trends, June 28, 2004, http://smallbiztrends.com/2004/06/marketing-to-opinion-leaders.html (accessed October 13, 2009). As you can probably tell from this chapter, exploring the frontiers of people’s buying patterns is a fascinating and constantly evolving field. The Consumer’s Family Most market researchers consider a person’s family to be one of the biggest determiners of buying behavior. Like it or not, you are more like your parents than you think, at least in terms of your consumption patterns. The fact is that many of the things you buy and don’t buy are a result of what your parents do and do not buy. The soap you grew up using, toothpaste your parents bought and used, and even the “brand” of politics you lean toward (Democratic or Republican) are examples of the products you are likely to favor as an adult. Family buying behavior has been researched extensively. Companies are also interested in which family members have the most influence over certain purchases. Children have a great deal of influence over many household purchases. For example, in 2003 nearly half (47 percent) of nine- to seventeen-year-olds were asked by parents to go online to find out about products or services, compared to 37 percent in 2001. IKEA used this knowledge to design their showrooms. The children’s bedrooms feature fun beds with appealing comforters so children will be prompted to identify and ask for what they want. “Teen Market Profile,” Mediamark Research, 2003, http://www.magazine.org/content/files/teenprofile04.pdf (accessed December 4, 2009). Marketing to children has come under increasing scrutiny. Some critics accuse companies of deliberating manipulating children to nag their parents for certain products. For example, even though tickets for Hannah Montana concerts ranged from hundreds to thousands of dollars, the concerts often still sold out. However, as one writer put it, exploiting “pester power” is not always ultimately in the long-term interests of advertisers if it alienates kids’ parents. Ray Waddell, “Miley Strikes Back,” Billboard, June 27, 2009, 7–8. Key Takeaway Culture prescribes the way in which you should live and affects the things you purchase. A subculture is a group of people within a culture who are different from the dominant culture but have something in common with one another—common interests, vocations or jobs, religions, ethnic backgrounds, sexual orientations, and so forth. To some degree, consumers in the same social class exhibit similar purchasing behavior. Most market researchers consider a person’s family to be one of the biggest determiners of buying behavior. Reference groups are groups that a consumer identifies with and wants to join. Companies often hire celebrities to endorse their products to appeal to people’s reference groups. Opinion leaders are people with expertise in certain areas. Consumers respect these people and often ask their opinions before they buy goods and services. Review Questions Why do people’s cultures affect what they buy? How do subcultures differ from cultures? Can you belong to more than one culture or subculture? How are companies trying to reach opinion leaders today? 3.6 Discussion Questions and Activities Discussion Questions Why do people in different cultures buy different products? Discuss with your class the types of vehicles you have seen other countries. Why are they different, and how do they better meet buyers’ needs in those countries? What types of cars do you think should be sold in the United States today? What is your opinion of companies like Google that gather information about your browsing patterns? What advantages and drawbacks does this pose for consumers? If you were a business owner, what kinds of information would you gather on your customers and how would you use it? Are there any areas in which you consider yourself an opinion leader? What are they? What purchasing decisions have you been able to influence in your family and why? Is marketing to children a good idea? If not, what if one of your competitors were successfully do so? Would it change your opinion? How do you determine what is distinctive about different groups? What distinguishes one group from other groups? Name some products that have led to postpurchase dissonance on your part. Then categorize them as high- or low-involvement products. Describe the decision process for impulse purchases at the retail level. Would they be classified as high- or low-involvement purchases? How do you think the manufacturers of products sold through infomercials reduce postpurchase dissonance? Explain the relationship between extensive, limited, and routine decision making relative to high and low involvement. Identify examples of extensive, limited, and routine decision making based on your personal consumption behavior. Activities Go to http://www.ospreypacks.com and enter the blog site. Does the blog make you more or less inclined to purchase an Osprey backpack? Select three advertisements and describe the needs identified by Maslow that each ad addresses. Break up into groups and visit an ethnic part of your town that differs from your own ethnicity (ies). Walk around the neighborhood and its stores. What types of marketing and buying differences do you see? Write a report of your findings. Using Maslow’s Hierarchy of Needs, identify a list of popular advertising slogans that appeal to each of the five levels. Identify how McDonald’s targets both users (primarily children) and buyers (parents, grandparents, etc.). Provide specific examples of strategies used by the fast-food marketer to target both groups. Make it a point to incorporate Happy Meals and Mighty Kids Meals into your discussion.	msmarco_doc_00_12151675
http://2012books.lardbucket.org/books/marketing-principles-v1.0/s13-02-steps-in-the-marketing-researc.html	Steps in the Marketing Research Process	10.2 Steps in the Marketing Research Process 10.2 Steps in the Marketing Research Process Learning Objective Step 1: Define the Problem (or Opportunity) Video Clip Video Clip Step 2: Design the Research Sources of Secondary Data Gauging the Quality of Secondary Data Gauging the Credibility of Secondary Data: Questions to Ask Types of Research Design The Basic Steps of Conducting a Focus Group Video Clip Descriptive Research Causal Research Step 3: Design the Data-Collection Forms Questionnaire Design Testing the Questionnaire Step 4: Specify the Sample Step 5: Collect the Data Video Clip Collecting International Marketing Research Data Step 6: Analyze the Data Stage 7: Write the Research Report and Present Its Findings Key Takeaway	Steps in the Marketing Research Process 10.2 Steps in the Marketing Research Process Learning Objective Describe the basic steps in the marketing research process and the purpose of each step. The basic steps used to conduct marketing research are shown in Figure 10.6 "Steps in the Marketing Research Process". Next, we discuss each step. Figure 10.6 Steps in the Marketing Research Process Step 1: Define the Problem (or Opportunity) There’s a saying in marketing research that a problem half defined is a problem half solved. Defining the “problem” of the research sounds simple, doesn’t it? Suppose your product is tutoring other students in a subject you’re a whiz at. You have been tutoring for a while, and people have begun to realize you’re darned good at it. Then, suddenly, your business drops off. Or it explodes, and you can’t cope with the number of students you’re being asked help. If the business has exploded, should you try to expand your services? Perhaps you should subcontract with some other “whiz” students. You would send them students to be tutored, and they would give you a cut of their pay for each student you referred to them. Both of these scenarios would be a problem for you, wouldn’t they? They are problems insofar as they cause you headaches. But are they really the problem? Or are they the symptoms of something bigger? For example, maybe your business has dropped off because your school is experiencing financial trouble and has lowered the number of scholarships given to incoming freshmen. Consequently, there are fewer total students on campus who need your services. Conversely, if you’re swamped with people who want you to tutor them, perhaps your school awarded more scholarships than usual, so there are a greater number of students who need your services. Alternately, perhaps you ran an ad in your school’s college newspaper, and that led to the influx of students wanting you to tutor them. Businesses are in the same boat you are as a tutor. They take a look at symptoms and try to drill down to the potential causes. If you approach a marketing research company with either scenario—either too much or too little business—the firm will seek more information from you such as the following: In what semester (s) did your tutoring revenues fall (or rise)? In what subject areas did your tutoring revenues fall (or rise)? In what sales channels did revenues fall (or rise): Were there fewer (or more) referrals from professors or other students? Did the ad you ran result in fewer (or more) referrals this month than in the past months? Among what demographic groups did your revenues fall (or rise)—women or men, people with certain majors, or first-year, second-, third-, or fourth-year students? The key is to look at all potential causes so as to narrow the parameters of the study to the information you actually need to make a good decision about how to fix your business if revenues have dropped or whether or not to expand it if your revenues have exploded. The next task for the researcher is to put into writing the research objective. The research objective The goal (s) marketing research is supposed to accomplish. is the goal (s) the research is supposed to accomplish. The marketing research objective for your tutoring business might read as follows: To survey college professors who teach 100- and 200-level math courses to determine why the number of students referred for tutoring dropped in the second semester. This is admittedly a simple example designed to help you understand the basic concept. If you take a marketing research course, you will learn that research objectives get a lot more complicated than this. The following is an example: “To gather information from a sample representative of the U.S. population among those who are “very likely” to purchase an automobile within the next 6 months, which assesses preferences (measured on a 1–5 scale ranging from “very likely to buy” to “not likely at all to buy”) for the model diesel at three different price levels. Such data would serve as input into a forecasting model that would forecast unit sales, by geographic regions of the country, for each combination of the model’s different prices and fuel configurations. Alvin Burns and Ronald Bush, Marketing Research, 6th ed. (Upper Saddle River, NJ: Prentice Hall, 2010), 85. ” Now do you understand why defining the problem is complicated and half the battle? Many a marketing research effort is doomed from the start because the problem was improperly defined. Coke’s ill-fated decision to change the formula of Coca-Cola in 1985 is a case in point: Pepsi had been creeping up on Coke in terms of market share over the years as well as running a successful promotional campaign called the “Pepsi Challenge,” in which consumers were encouraged to do a blind taste test to see if they agreed that Pepsi was better. Coke spent four years researching “the problem.” Indeed, people seemed to like the taste of Pepsi better in blind taste tests. Thus, the formula for Coke was changed. But the outcry among the public was so great that the new formula didn’t last long—a matter of months—before the old formula was reinstated. Some marketing experts believe Coke incorrectly defined the problem as “How can we beat Pepsi in taste tests?” instead of “How can we gain market share against Pepsi?” Alvin Burns and Ronald Bush, Marketing Research, 6th ed. (Upper Saddle River, NJ: Prentice Hall, 2010), 87–88. Video Clip New Coke Is It! 1985 (click to see video) This video documents the Coca-Cola Company’s ill-fated launch of New Coke in 1985. Video Clip 1985 Pepsi Commercial—“They Changed My Coke” (click to see video) This video shows how Pepsi tried to capitalize on the blunder. Step 2: Design the Research The next step in the marketing research process is to do a research design. The research design An outline that specifies the research data to be gathered, from whom, how, and when the data will be analyzed once it has been obtained. is your “plan of attack.” It outlines what data you are going to gather and from whom, how and when you will collect the data, and how you will analyze it once it’s been obtained. Let’s look at the data you’re going to gather first. There are two basic types of data you can gather. The first is primary data. Primary data Data collected using hands-on tools such as interviews or surveys to answer a question for a specific research project. is information you collect yourself, using hands-on tools such as interviews or surveys, specifically for the research project you’re conducting. Secondary data Data already collected by your firm or another organization for purposes other than the marketing research project at hand. is data that has already been collected by someone else, or data you have already collected for another purpose. Collecting primary data is more time consuming, work intensive, and expensive than collecting secondary data. Consequently, you should always try to collect secondary data first to solve your research problem, if you can. A great deal of research on a wide variety of topics already exists. If this research contains the answer to your question, there is no need for you to replicate it. Why reinvent the wheel? Sources of Secondary Data Your company’s internal records are a source of secondary data. So are any data you collect as part of your marketing intelligence gathering efforts. You can also purchase syndicated research. Syndicated research Primary data marketing research firms collect on a regular basis and sell to other companies. is primary data that marketing research firms collect on a regular basis and sell to other companies. J.D. Power & Associates is a provider of syndicated research. The company conducts independent, unbiased surveys of customer satisfaction, product quality, and buyer behavior for various industries. The company is best known for its research in the automobile sector. One of the best-known sellers of syndicated research is the Nielsen Company, which produces the Nielsen ratings. The Nielsen ratings measure the size of television, radio, and newspaper audiences in various markets. You have probably read or heard about TV shows that get the highest (Nielsen) ratings. Nielsen, along with its main competitor, Information Resources, Inc. (IRI), also sells businesses scanner-based research Information collected by scanners at checkout stands in stores. . Scanner-based research is information collected by scanners at checkout stands in stores. Each week Nielsen and IRI collect information on the millions of purchases made at stores. The companies then compile the information and sell it to firms in various industries that subscribe to their services. The Nielsen Company has also recently teamed up with Facebook to collect marketing research information. Via Facebook, users will see surveys in some of the spaces in which they used to see online ads. Alan Rappeport and David Gelles, “Facebook to Form Alliance with Nielsen,” Financial Times, September 23, 2009, 16. By contrast, MarketResearch.com is an example of a marketing research aggregator. A marketing research aggregator A marketing research company that doesn’t conduct its own research but instead buys it from other marketing research companies and then sells the reports in their entirety or in pieces to other firms. is a marketing research company that doesn’t conduct its own research and sell it. Instead, it buys research reports from other marketing research companies and then sells the reports in their entirety or in pieces to other firms. Check out MarketResearch.com’s Web site. As you will see there are a huge number of studies in every category imaginable that you can buy for relatively small amounts of money. Figure 10.7 Market research aggregators buy research reports from other marketing research companies and then resell them in part or in whole to other companies so they don’t have to gather primary data. Source: http://www.marketresearch.com. Your local library is a good place to gather free secondary data. It has searchable databases as well as handbooks, dictionaries, and books, some of which you can access online. Government agencies also collect and report information on demographics, economic and employment data, health information, and balance-of-trade statistics, among a lot of other information. The U.S. Census Bureau collects census data every ten years to gather information about who lives where. Basic demographic information about sex, age, race, and types of housing in which people live in each U.S. state, metropolitan area, and rural area is gathered so that population shifts can be tracked for various purposes, including determining the number of legislators each state should have in the U.S. House of Representatives. For the U.S. government, this is primary data. For marketing managers it is an important source of secondary data. The Survey Research Center at the University of Michigan also conducts periodic surveys and publishes information about trends in the United States. One research study the center continually conducts is called the “Changing Lives of American Families” ( http://www.isr.umich.edu/home/news/research-update/2007-01.pdf ). This is important research data for marketing managers monitoring consumer trends in the marketplace. The World Bank and the United Nations are two international organizations that collect a great deal of information. Their Web sites contain many free research studies and data related to global markets. Table 10.1 "Examples of Primary Data Sources versus Secondary Data Sources" shows some examples of primary versus secondary data sources. Table 10.1 Examples of Primary Data Sources versus Secondary Data Sources Primary Data Sources Secondary Data Sources Interviews Census data Surveys Web sites Publications Trade associations Syndicated research and market aggregators Gauging the Quality of Secondary Data When you are gathering secondary information, it’s always good to be a little skeptical of it. Sometimes studies are commissioned to produce the result a client wants to hear—or wants the public to hear. For example, throughout the twentieth century, numerous studies found that smoking was good for people’s health. The problem was the studies were commissioned by the tobacco industry. Web research can also pose certain hazards. There are many biased sites that try to fool people that they are providing good data. Often the data is favorable to the products they are trying to sell. Beware of product reviews as well. Unscrupulous sellers sometimes get online and create bogus ratings for products. See below for questions you can ask to help gauge the credibility of secondary information. Gauging the Credibility of Secondary Data: Questions to Ask Who gathered this information? For what purpose? What does the person or organization that gathered the information have to gain by doing so? Was the information gathered and reported in a systematic manner? Is the source of the information accepted as an authority by other experts in the field? Does the article provide objective evidence to support the position presented? Types of Research Design Now let’s look specifically at the types of research designs that are utilized. By understanding different types of research designs, a researcher can solve a client’s problems more quickly and efficiently without jumping through more hoops than necessary. Research designs fall into one of the following three categories: Exploratory research design Descriptive research design Causal research design (experiments) An exploratory research design A less-structured type of research design used to initially investigate a marketing research project that hasn’t yet been defined well enough for an in-depth study to be conducted. is useful when you are initially investigating a problem but you haven’t defined it well enough to do an in-depth study of it. Perhaps via your regular market intelligence, you have spotted what appears to be a new opportunity in the marketplace. You would then do exploratory research to investigate it further and “get your feet wet,” as the saying goes. Exploratory research is less structured than other types of research, and secondary data is often utilized. The depth interview An exploratory research technique of engaging in detailed, one-on-one, question-and-answer sessions with potential buyers. —engaging in detailed, one-on-one, question-and-answer sessions with potential buyers—is an exploratory research technique. However, unlike surveys, the people being interviewed aren’t asked a series of standard questions. Instead the interviewer is armed with some general topics and asks questions that are open ended, meaning that they allow the interviewee to elaborate. “How did you feel about the product after you purchased it?” is an example of a question that might be asked. A depth interview also allows a researcher to ask logical follow-up questions such as “Can you tell me what you mean when you say you felt uncomfortable using the service?” or “Can you give me some examples?” to help dig further and shed additional light on the research problem. Depth interviews can be conducted in person or over the phone. The interviewer either takes notes or records the interview. Focus groups and case studies are often utilized for exploratory research as well. A focus group A group of potential buyers brought together to discuss a marketing research topic with one another. is a group of potential buyers who are brought together to discuss a marketing research topic with one another. A moderator is used to focus the discussion, the sessions are recorded, and the main points of consensus are later summarized by the market researcher. Textbook publishers often gather groups of professors at educational conferences to participate in focus groups. However, focus groups can also be conducted on the telephone, in online chat rooms, or both, using meeting software like WebEx. The basic steps of conducting a focus group are outlined below. The Basic Steps of Conducting a Focus Group Establish the objectives of the focus group. What is its purpose? Identify the people who will participate in the focus group. What makes them qualified to participate? How many of them will you need and what they will be paid? Obtain contact information for the participants and send out invitations (usually e-mails are most efficient). Develop a list of questions. Choose a facilitator. Choose a location in which to hold the focus group and the method by which it will be recorded. Conduct the focus group. If the focus group is not conducted electronically, include name tags for the participants, pens and notepads, any materials the participants need to see, and refreshments. Record participants’ responses. Summarize the notes from the focus group and write a report for management. A case study A study that looks at how another company, or companies, solved a problem being researched. looks at how another company solved the problem that’s being researched. Sometimes multiple cases, or companies, are used in a study. Case studies nonetheless have a mixed reputation. Some researchers believe it’s hard to generalize, or apply, the results of a case study to other companies. Nonetheless, collecting information about companies that encountered the same problems your firm is facing can give you a certain amount of insight about what direction you should take. In fact, one way to begin a research project is to carefully study a successful product or service. Two other types of qualitative data used for exploratory research are ethnographies and projective techniques. In an ethnography A type of study whereby marketing researchers interview, observe, and often videotape people while they work, live, shop, and play. , researchers interview, observe, and often videotape people while they work, live, shop, and play. The Walt Disney Company has recently begun using ethnographers to uncover the likes and dislikes of boys aged six to fourteen. This is a financially attractive market segment for Disney, but one in which the company has been losing market share. The ethnographers visit the homes of boys, observe the things they have in their rooms to get a sense of their hobbies, and accompany them and their mothers when they shop to see where they go, what the boys are interested in, and what they ultimately buy. (The children get seventy-five dollars out of the deal, incidentally.) Brook Barnes, “Disney Expert Uses Science to Draw Boy Viewers,” New York Times, April 15, 2009, http://www.nytimes.com/2009/04/14/arts/television/14boys.html?pagewanted=1&_r=1 (accessed December 14, 2009). Projective techniques An exploratory research technique used to reveal information research respondents might not reveal by being asked directly. are used to reveal information research respondents might not reveal by being asked directly. Asking a person to complete sentences such as the following is one technique: People who buy Coach handbags __________. (Will he or she reply with “are cool,” “are affluent,” or “are pretentious,” for example?) KFC’s grilled chicken is ______. Or the person might be asked to finish a story that presents a certain scenario. Word associations are also used to discern people’s underlying attitudes toward goods and services. Using a word-association technique, a market researcher asks a person to say or write the first word that comes to his or her mind in response to another word. If the initial word is “fast food,” what word does the person associate it with or respond with? Is it “McDonald’s”? If many people reply that way, and you’re conducting research for Burger King, that could indicate Burger King has a problem. However, if the research is being conducted for Wendy’s, which recently began running an advertising campaign to the effect that Wendy’s offerings are “better than fast food,” it could indicate that the campaign is working. Completing cartoons is yet another type of projective technique. It’s similar to finishing a sentence or story, only with the pictures. People are asked to look at a cartoon such as the one shown in Figure 10.8 "Example of a Cartoon-Completion Projective Technique". One of the characters in the picture will have made a statement, and the person is asked to fill in the empty cartoon “bubble” with how they think the second character will respond. Figure 10.8 Example of a Cartoon-Completion Projective Technique In some cases, your research might end with exploratory research. Perhaps you have discovered your organization lacks the resources needed to produce the product. In other cases, you might decide you need more in-depth, quantitative research such as descriptive research or causal research, which are discussed next. Most marketing research professionals advise using both types of research, if it’s feasible. On the one hand, the qualitative-type research used in exploratory research is often considered too “lightweight.” Remember earlier in the chapter when we discussed telephone answering machines and the hit TV sitcom Seinfeld? Both product ideas were initially rejected by focus groups. On the other hand, relying solely on quantitative information often results in market research that lacks ideas. Video Clip The Stone Wheel—What One Focus Group Said (click to see video) Watch the video to see a funny spoof on the usefulness—or lack of usefulness—of focus groups. Descriptive Research Anything that can be observed and counted falls into the category of descriptive research design. A study using a descriptive research design A study that involves gathering hard numbers, often via surveys, to describe or measure a phenomenon so as to answer the questions of who, what, where, when, and how. involves gathering hard numbers, often via surveys, to describe or measure a phenomenon so as to answer the questions of who, what, where, when, and how. “On a scale of 1–5, how satisfied were you with your service?” is a question that illustrates the information a descriptive research design is supposed to capture. Physiological measurements also fall into the category of descriptive design. Physiological measurements Measurements that record people’s involuntary physical responses to marketing stimuli, such as an advertisement. measure people’s involuntary physical responses to marketing stimuli, such as an advertisement. Recall in Chapter 3 "Consumer Behavior: How People Make Buying Decisions" we explained that researchers have gone so far as to scan the brains of consumers to see what they really think about products versus what they say about them. Eye tracking is another cutting-edge type of physiological measurement. It involves recording the movements of a person’s eyes when they look at some sort of stimulus, such as a banner ad or a Web page. The Walt Disney Company has a research facility in Austin, Texas, that it uses to take physical measurements of viewers when they see Disney programs and advertisements. The facility measures three types of responses: people’s heart rates, skin changes, and eye movements (eye tracking). Todd Spangler, “Disney Lab Tracks Feelings,” Multichannel News 30, no. 30 (August 3, 2009): 26. Figure 10.9 A woman shows off her headgear for an eye-tracking study. The gear’s not exactly a fashion statement but . . . Source: http://www.jasonbabcock.com/eyetracking_hardware.html. A strictly descriptive research design instrument—a survey, for example—can tell you how satisfied your customers are. It can’t, however, tell you why. Nor can an eye-tracking study tell you why people’s eyes tend to dwell on certain types of banner ads—only that they do. To answer “why” questions an exploratory research design or causal research design is needed. James Wagner, “Marketing in Second Life Doesn’t Work…Here Is Why!” GigaOM, April 4, 2007, http://gigaom.com/2007/04/04/3-reasons-why-marketing-in-second-life-doesnt-work (accessed December 14, 2009). Causal Research Causal research design A type of research design that examines cause-and-effect relationships to allow researchers to answer “what if” types of questions. examines cause-and-effect relationships. Using a causal research design allows researchers to answer “what if” types of questions. In other words, if a firm changes X (say, a product’s price, design, placement, or advertising), what will happen to Y (say, sales or customer loyalty)? To conduct causal research, the researcher designs an experiment that “controls,” or holds constant, all of a product’s marketing elements except one. The one variable is changed, and the effect is then measured. Sometimes the experiments are conducted in a laboratory using a simulated setting designed to replicate the conditions buyers would experience. Or the experiments may be conducted in a virtual computer setting. You might think setting up an experiment in a virtual world such as the online game Second Life would be a viable way to conduct controlled marketing research. Some companies have tried to use Second Life for this purpose, but the results have been somewhat mixed as to whether or not it is a good medium for marketing research. The German marketing research firm Komjuniti was one of the first “real-world” companies to set up an “island” in Second Life upon which it could conduct marketing research. However, with so many other attractive fantasy islands in which to play, the company found it difficult to get Second Life residents, or players, to voluntarily visit the island and stay long enough so meaningful research could be conducted. (Plus, the “residents,” or players, in Second Life have been known to protest corporations invading their world. When the German firm Komjuniti created an island in Second Life to conduct marketing research, the residents showed up waving signs and threatening to boycott the island.) James Wagner, “Marketing in Second Life Doesn’t Work…Here Is Why!” GigaOM, April 4, 2007, http://gigaom.com/2007/04/04/3-reasons-why-marketing-in-second-life-doesnt-work/ (accessed December 14, 2009). Why is being able to control the setting so important? Let’s go back to our American flag example. Suppose prior to 9/11 Walmart had been in the process of conducting an experiment to see where in its stores American flags should be placed so as to increase their sales. Obviously, the terrorist attacks in the United States would have skewed the experiment’s data. An experiment conducted in a natural setting such as a store is referred to as a field experiment A marketing research experiment conducted in a natural setting such as a store versus a simulated setting in a laboratory or on a computer. . Companies sometimes do field experiments either because it is more convenient or because they want to see if buyers will behave the same way in the “real world” as in a laboratory or on a computer. The place the experiment is conducted or the demographic group of people the experiment is administered to is considered the test market The place an experiment is conducted or the demographic group of people an experiment is administered to. . Before a large company rolls out a product to the entire marketplace, it will often place the offering in a test market to see how well it will be received. For example, to compete with MillerCoors’ sixty-four-calorie beer MGD 64, Anheuser-Busch recently began testing its Select 55 beer in certain cities around the country. Jeremiah McWilliams, “A-B Puts Super-Low-Calorie Beer in Ring with Miller,” St. Louis Post-Dispatch, August 16, 2009, http://www.stltoday.com/business/next-matchup-light-weights-a-b-puts-super-low-calorie/article_47511bfe-18ca-5979-bdb9-0526c97d4edf.html (accessed April 13, 2012). Figure 10.10 Select 55 beer: Coming soon to a test market near you? (If you’re on a diet, you have to hope so!) © 2010 Jupiterimages Corporation Many companies use experiments to test all of their marketing communications. For example, the online discount retailer Overstock.com carefully tests all of its marketing offers and tracks the results of each one. One study the company conducted combined twenty-six different variables related to offers e-mailed to several thousand customers. The study resulted in a decision to send a group of e-mails to different segments. The company then tracked the results of the sales generated to see if they were in line with the earlier experiment it had conducted that led it to make the offer. Step 3: Design the Data-Collection Forms If the behavior of buyers is being formally observed, and a number of different researchers are conducting observations, the data obviously need to be recorded on a standardized data-collection form that’s either paper or electronic. Otherwise, the data collected will not be comparable. The items on the form could include a shopper’s sex; his or her approximate age; whether the person seemed hurried, moderately hurried, or unhurried; and whether or not he or she read the label on products, used coupons, and so forth. The same is true when it comes to surveying people with questionnaires. Surveying people is one of the most commonly used techniques to collect quantitative data. Surveys are popular because they can be easily administered to large numbers of people fairly quickly. However, to produce the best results, the questionnaire for the survey needs to be carefully designed. Questionnaire Design Most questionnaires follow a similar format: They begin with an introduction describing what the study is for, followed by instructions for completing the questionnaire and, if necessary, returning it to the market researcher. The first few questions that appear on the questionnaire are usually basic, warm-up type of questions the respondent can readily answer, such as the respondent’s age, level of education, place of residence, and so forth. The warm-up questions are then followed by a logical progression of more detailed, in-depth questions that get to the heart of the question being researched. Lastly, the questionnaire wraps up with a statement that thanks the respondent for participating in the survey and information and explains when and how they will be paid for participating. To see some examples of questionnaires and how they are laid out, click on the following link: http://cas.uah.edu/wrenb/mkt343/Project/Sample%20Questionnaires.htm. How the questions themselves are worded is extremely important. It’s human nature for respondents to want to provide the “correct” answers to the person administering the survey, so as to seem agreeable. In other words, there is always a hazard that people will try to tell you what you want to hear on a survey. Consequently, care needs to be taken that the survey questions are written in an unbiased, neutral way. In other words, they shouldn’t lead a person taking the questionnaire to answer a question one way or another by virtue of the way you have worded it. The following is an example of a leading question. Don’t you agree that teachers should be paid more? The questions also need to be clear and unambiguous. Consider the following question: Which brand of toothpaste do you use? The question sounds clear enough, but is it really? What if the respondent recently switched brands? What if she uses Crest at home, but while away from home or traveling, she uses Colgate’s Wisp portable toothpaste-and-brush product? How will the respondent answer the question? Rewording the question as follows so it’s more specific will help make the question clearer: Which brand of toothpaste have you used at home in the past six months? If you have used more than one brand, please list each of them. “Questionnaire Design,” QuickMBA, http://www.quickmba.com/marketing/research/qdesign (accessed December 14, 2009). Sensitive questions have to be asked carefully. For example, asking a respondent, “Do you consider yourself a light, moderate, or heavy drinker?” can be tricky. Few people want to admit to being heavy drinkers. You can “soften” the question by including a range of answers, as the following example shows: How many alcoholic beverages do you consume in a week? __0–5 alcoholic beverages __5–10 alcoholic beverages __10–15 alcoholic beverages Many people don’t like to answer questions about their income levels. Asking them to specify income ranges rather than divulge their actual incomes can help. Other research question “don’ts” include using jargon and acronyms that could confuse people. “How often do you IM?” is an example. Also, don’t muddy the waters by asking two questions in the same question, something researchers refer to as a double-barreled question A survey question that is potentially confusing because it asks two questions in the same question. . “Do you think parents should spend more time with their children and/or their teachers?” is an example of a double-barreled question. Open-ended questions Questions that ask respondents to elaborate upon, or explain, their answers. , or questions that ask respondents to elaborate, can be included. However, they are harder to tabulate than closed-ended questions Questions that limit a respondent’s answers. Multiple-choice and yes-and-no questions are examples of closed-ended questions. , or questions that limit a respondent’s answers. Multiple-choice and yes-and-no questions are examples of closed-ended questions. Testing the Questionnaire You have probably heard the phrase “garbage in, garbage out.” If the questions are bad, the information gathered will be bad, too. One way to make sure you don’t end up with garbage is to test the questionnaire before sending it out to find out if there are any problems with it. Is there enough space for people to elaborate on open-ended questions? Is the font readable? To test the questionnaire, marketing research professionals first administer it to a number of respondents face to face. This gives the respondents the chance to ask the researcher about questions or instructions that are unclear or don’t make sense to them. The researcher then administers the questionnaire to a small subset of respondents in the actual way the survey is going to be disseminated, whether it’s delivered via phone, in person, or by mail. Getting people to participate and complete questionnaires can be difficult. If the questionnaire is too long or hard to read, many people won’t complete it. So, by all means, eliminate any questions that aren’t necessary. Of course, including some sort of monetary incentive for completing the survey can increase the number of completed questionnaires a market researcher will receive. Step 4: Specify the Sample Once you have created your questionnaire or other marketing study, how do you figure out who should participate in it? Obviously, you can’t survey or observe all potential buyers in the marketplace. Instead, you must choose a sample. A sample A small amount of a product given to consumers to try for free. is a subset of potential buyers that are representative of your entire target market, or population The entire target market being studied. being studied. Sometimes market researchers refer to the population as the universe to reflect the fact that it includes the entire target market, whether it consists of a million people, a hundred thousand, a few hundred, or a dozen. “All unmarried people over the age of eighteen who purchased Dirt Devil steam cleaners in the United States during 2009” is an example of a population that has been defined. Obviously, the population has to be defined correctly. Otherwise, you will be studying the wrong group of people. Not defining the population correctly can result in flawed research, or sampling error. A sampling error Any type of marketing research mistake that results because a sample was utilized. is any type of marketing research mistake that results because a sample was utilized. One criticism of Internet surveys is that the people who take these surveys don’t really represent the overall population. On average, Internet survey takers tend to be more educated and tech savvy. Consequently, if they solely constitute your population, even if you screen them for certain criteria, the data you collect could end up being skewed. The next step is to put together the sampling frame The list from which a research sample is drawn. The sampling frame won’t perfectly match the population. , which is the list from which the sample is drawn. The sampling frame can be put together using a directory, customer list, or membership roster. Bruce Wrenn, Robert E. Stevens, and David L. Loudon, Marketing Research: Text and Cases, 2nd ed. (Binghamton, NY: Haworth Press, 2007), 180. Keep in mind that the sampling frame won’t perfectly match the population. Some people will be included on the list who shouldn’t be. Other people who should be included will be inadvertently omitted. It’s no different than if you were to conduct a survey of, say, 25 percent of your friends, using friends’ names you have in your mobile phone. Most of your friends’ names are likely to be programmed into your phone, but not all of them. As a result, a certain degree of sampling error always occurs. There are two main categories of samples in terms of how they are drawn: probability samples and nonprobability samples. A probability sample A research sample in which each would-be participant has a known and equal chance of being selected. is one in which each would-be participant has a known and equal chance of being selected. The chance is known because the total number of people in the sampling frame is known. For example, if every other person from the sampling frame were chosen, each person would have a 50 percent chance of being selected. A nonprobability sample A research sample that’s not drawn in a systematic way. is any type of sample that’s not drawn in a systematic way. So the chances of each would-be participant being selected can’t be known. A convenience sample Type of nonprobability sample that’s drawn because it’s readily available and convenient to do so. is one type of nonprobability sample. It is a sample a researcher draws because it’s readily available and convenient to do so. Surveying people on the street as they pass by is an example of a convenience sample. The question is, are these people representative of the target market? For example, suppose a grocery store needed to quickly conduct some research on shoppers to get ready for an upcoming promotion. Now suppose that the researcher assigned to the project showed up between the hours of 10 a.m. and 12 p.m. on a weekday and surveyed as many shoppers as possible. The problem is that the shoppers wouldn’t be representative of the store’s entire target market. What about commuters who stop at the store before and after work? Their views wouldn’t be represented. Neither would people who work the night shift or shop at odd hours. As a result, there would be a lot of room for sampling error in this study. For this reason, studies that use nonprobability samples aren’t considered as accurate as studies that use probability samples. Nonprobability samples are more often used in exploratory research. Lastly, the size of the sample has an effect on the amount of sampling error. Larger samples generally produce more accurate results. The larger your sample is, the more data you will have, which will give you a more complete picture of what you’re studying. However, the more people surveyed or studied, the more costly the research becomes. Statistics can be used to determine a sample’s optimal size. If you take a marketing research or statistics class, you will learn more about how to determine the optimal size. Of course, if you hire a marketing research company, much of this work will be taken care of for you. Many marketing research companies maintain panels of prescreened people they draw upon for samples. In addition, the marketing research firm will be responsible for collecting the data or contracting with a company that specializes in data collection. Data collection is discussed next. Step 5: Collect the Data As we have explained, primary marketing research data can be gathered in a number of ways. Surveys, taking physical measurements, and observing people are just three of the ways we discussed. If you’re observing customers as part of gathering the data, keep in mind that if shoppers are aware of the fact, it can have an effect on their behavior. For example, if a customer shopping for feminine hygiene products in a supermarket aisle realizes she is being watched, she could become embarrassed and leave the aisle. This would adversely affect your data. To get around problems such as these, some companies set up cameras or two-way mirrors to observe customers. Organizations also hire mystery shoppers to work around the problem. A mystery shopper A person who is paid to shop at a firm’s establishment or one of its competitors’ to observe the level of service, cleanliness of the facility, and so forth, and report his or her findings to the firm. is someone who is paid to shop at a firm’s establishment or one of its competitors to observe the level of service, cleanliness of the facility, and so forth, and report his or her findings to the firm. Video Clip Make Extra Money as a Mystery Shopper (click to see video) Watch the YouTube video to get an idea of how mystery shopping works. Survey data can be collected in many different ways and combinations of ways. The following are the basic methods used: Face-to-face (can be computer aided) Telephone (can be computer aided or completely automated) Mail and hand delivery E-mail and the Web A face-to-face survey is, of course, administered by a person. The surveys are conducted in public places such as in shopping malls, on the street, or in people’s homes if they have agreed to it. In years past, it was common for researchers in the United States to knock on people’s doors to gather survey data. However, randomly collected door-to-door interviews are less common today, partly because people are afraid of crime and are reluctant to give information to strangers. Carl D. McDaniel and Roger H. Gates, Marketing Research Essentials, 2nd ed. (Cincinnati: South-Western College Publishing, 1998), 61. Nonetheless, “beating the streets” is still a legitimate way questionnaire data is collected. When the U.S. Census Bureau collects data on the nation’s population, it hand delivers questionnaires to rural households that do not have street-name and house-number addresses. And Census Bureau workers personally survey the homeless to collect information about their numbers. Face-to-face surveys are also commonly used in third world countries to collect information from people who cannot read or lack phones and computers. A plus of face-to-face surveys is that they allow researchers to ask lengthier, more complex questions because the people being surveyed can see and read the questionnaires. The same is true when a computer is utilized. For example, the researcher might ask the respondent to look at a list of ten retail stores and rank the stores from best to worst. The same question wouldn’t work so well over the telephone because the person couldn’t see the list. The question would have to be rewritten. Another drawback with telephone surveys is that even though federal and state “do not call” laws generally don’t prohibit companies from gathering survey information over the phone, people often screen such calls using answering machines and caller ID. Probably the biggest drawback of both surveys conducted face-to-face and administered over the phone by a person is that they are labor intensive and therefore costly. Mailing out questionnaires is costly, too, and the response rates can be rather low. Think about why that might be so: if you receive a questionnaire in the mail, it is easy to throw it in the trash; it’s harder to tell a market researcher who approaches you on the street that you don’t want to be interviewed. By contrast, gathering survey data collected by a computer, either over the telephone or on the Internet, can be very cost effective and in some cases free. SurveyMonkey and Zoomerang are two Web sites that will allow you to create online questionnaires, e-mail them to up to one hundred people for free, and view the responses in real time as they come in. For larger surveys, you have to pay a subscription price of a few hundred dollars. But that still can be extremely cost effective. The two Web sites also have a host of other features such as online-survey templates you can use to create your questionnaire, a way to set up automatic reminders sent to people who haven’t yet completed their surveys, and tools you can use to create graphics to put in your final research report. To see how easy it is to put together a survey in SurveyMonkey, click on the following link: http://help.surveymonkey.com/app/tutorials/detail/a_id/423. Like a face-to-face survey, an Internet survey can enable you to show buyers different visuals such as ads, pictures, and videos of products and their packaging. Web surveys are also fast, which is a major plus. Whereas face-to-face and mailed surveys often take weeks to collect, you can conduct a Web survey in a matter of days or even hours. And, of course, because the information is electronically gathered it can be automatically tabulated. You can also potentially reach a broader geographic group than you could if you had to personally interview people. The Zoomerang Web site allows you to create surveys in forty different languages. Another plus for Web and computer surveys (and electronic phone surveys) is that there is less room for human error because the surveys are administered electronically. For instance, there’s no risk that the interviewer will ask a question wrong or use a tone of voice that could mislead the respondents. Respondents are also likely to feel more comfortable inputting the information into a computer if a question is sensitive than they would divulging the information to another person face-to-face or over the phone. Given all of these advantages, it’s not surprising that the Internet is quickly becoming the top way to collect primary data. However, like mail surveys, surveys sent to people over the Internet are easy to ignore. Lastly, before the data collection process begins, the surveyors and observers need to be trained to look for the same things, ask questions the same way, and so forth. If they are using rankings or rating scales, they need to be “on the same page,” so to speak, as to what constitutes a high ranking or a low ranking. As an analogy, you have probably had some teachers grade your college papers harder than others. The goal of training is to avoid a wide disparity between how different observers and interviewers record the data. Figure 10.11 Training people so they know what constitutes different ratings when they are collecting data will improve the quality of the information gathered in a marketing research study. © 2010 Jupiterimages Corporation For example, if an observation form asks the observers to describe whether a shopper’s behavior is hurried, moderately hurried, or unhurried, they should be given an idea of what defines each rating. Does it depend on how much time the person spends in the store or in the individual aisles? How fast they walk? In other words, the criteria and ratings need to be spelled out. Collecting International Marketing Research Data Gathering marketing research data in foreign countries poses special challenges. However, that doesn’t stop firms from doing so. Marketing research companies are located all across the globe, in fact. Eight of the ten largest marketing research companies in the world are headquartered in the United States. However, five of these eight firms earn more of their revenues abroad than they do in the United States. There’s a reason for this: many U.S. markets were saturated, or tapped out, long ago in terms of the amount that they can grow. Coke is an example. As you learned earlier in the book, most of the Coca-Cola Company’s revenues are earned in markets abroad. To be sure, the United States is still a huge market when it comes to the revenues marketing research firms generate by conducting research in the country: in terms of their spending, American consumers fuel the world’s economic engine. Still, emerging countries with growing middle classes, such as China, India, and Brazil, are hot new markets companies want to tap. What kind of challenges do firms face when trying to conduct marketing research abroad? As we explained, face-to-face surveys are commonly used in third world countries to collect information from people who cannot read or lack phones and computers. However, face-to-face surveys are also common in Europe, despite the fact that phones and computers are readily available. In-home surveys are also common in parts of Europe. By contrast, in some countries, including many Asian countries, it’s considered taboo or rude to try to gather information from strangers either face-to-face or over the phone. In many Muslim countries, women are forbidden to talk to strangers. And how do you figure out whom to research in foreign countries? That in itself is a problem. In the United States, researchers often ask if they can talk to the heads of households to conduct marketing research. But in countries in which domestic servants or employees are common, the heads of households aren’t necessarily the principal shoppers; their domestic employees are. Naresh Malhotra, Marketing Research: An Applied Approach, 6th ed. (Upper Saddle River, NJ: Prentice Hall), 764. Translating surveys is also an issue. Have you ever watched the TV comedians Jay Leno and David Letterman make fun of the English translations found on ethnic menus and products? Research tools such as surveys can suffer from the same problem. Hiring someone who is bilingual to translate a survey into another language can be a disaster if the person isn’t a native speaker of the language to which the survey is being translated. One way companies try to deal with translation problems is by using back translation. When back translation A process whereby a native speaker translates a research instrument such as a survey into a foreign language and then back again to the original language to determine if there are gaps in meaning. is used, a native speaker translates the survey into the foreign language and then translates it back again to the original language to determine if there were gaps in meaning—that is, if anything was lost in translation. And it’s not just the language that’s an issue. If the research involves any visual images, they, too, could be a point of confusion. Certain colors, shapes, and symbols can have negative connotations in other countries. For example, the color white represents purity in many Western cultures, but in China, it is the color of death and mourning. Malika Zouhali-Worrall, “Found in Translation: Avoiding Multilingual Gaffes,” CNNMoney.com, July 14, 2008, http://money.cnn.com/2008/07/07/smallbusiness/language_translation.fsb/index.htm (accessed December 14, 2009). Also, look back at the cartoon-completion exercise in Figure 10.8 "Example of a Cartoon-Completion Projective Technique". What would women in Muslim countries who aren’t allowed to converse with male sellers think of it? Chances are, the cartoon wouldn’t provide you with the information you’re seeking if Muslim women in some countries were asked to complete it. One way marketing research companies are dealing with the complexities of global research is by merging with or acquiring marketing research companies abroad. The Nielsen Company is the largest marketing research company in the world. The firm operates in more than a hundred countries and employs more than forty thousand people. Many of its expansions have been the result of acquisitions and mergers. Step 6: Analyze the Data Step 6 involves analyzing the data to ensure it’s as accurate as possible. If the research is collected by hand using a pen and pencil, it’s entered into a computer. Or respondents might have already entered the information directly into a computer. For example, when Toyota goes to an event such as a car show, the automaker’s marketing personnel ask would-be buyers to complete questionnaires directly on computers. Companies are also beginning to experiment with software that can be used to collect data using mobile phones. Once all the data is collected, the researchers begin the data cleaning The process of removing research data that have accidentally been duplicated (entered twice into the computer) or correcting data that have obviously been recorded wrong. , which is the process of removing data that have accidentally been duplicated (entered twice into the computer) or correcting data that have obviously been recorded wrong. A program such as Microsoft Excel or a statistical program such as Predictive Analytics Software (PASW, which was formerly known as SPSS) is then used to tabulate, or calculate, the basic results of the research, such as the total number of participants and how collectively they answered various questions. The programs can also be used to calculate averages, such as the average age of respondents, their average satisfaction, and so forth. The same can done for percentages, and other values you learned about, or will learn about, in a statistics course, such as the standard deviation, mean, and median for each question. The information generated by the programs can be used to draw conclusions, such as what all customers might like or not like about an offering based on what the sample group liked or did not like. The information can also be used to spot differences among groups of people. For example, the research might show that people in one area of the country like the product better than people in another area. Trends to predict what might happen in the future can also be spotted. If there are any open-ended questions respondents have elaborated upon—for example, “Explain why you like the current brand you use better than any other brand”—the answers to each are pasted together, one on top of another, so researchers can compare and summarize the information. As we have explained, qualitative information such as this can give you a fuller picture of the results of the research. Part of analyzing the data is to see if it seems sound. Does the way in which the research was conducted seem sound? Was the sample size large enough? Are the conclusions that become apparent from it reasonable? The two most commonly used criteria used to test the soundness of a study are (1) validity and (2) reliability. A study is valid A study that actually tests what it was designed to test and not something else. if it actually tested what it was designed to test. For example, did the experiment you ran in Second Life test what it was designed to test? Did it reflect what could really happen in the real world? If not, the research isn’t valid. If you were to repeat the study, and get the same results (or nearly the same results), the research is said to be reliable A study that, when repeated, produces the same or nearly the same result. . If you get a drastically different result if you repeat the study, it’s not reliable. The data collected, or at least some it, can also be compared to, or reconciled with, similar data from other sources either gathered by your firm or by another organization to see if the information seems on target. Stage 7: Write the Research Report and Present Its Findings If you end up becoming a marketing professional and conducting a research study after you graduate, hopefully you will do a great job putting the study together. You will have defined the problem correctly, chosen the right sample, collected the data accurately, analyzed it, and your findings will be sound. At that point, you will be required to write the research report and perhaps present it to an audience of decision makers. You will do so via a written report and, in some cases, a slide or PowerPoint presentation based on your written report. The six basic elements of a research report are as follows. Title Page. The title page explains what the report is about, when it was conducted and by whom, and who requested it. Table of Contents. The table of contents outlines the major parts of the report, as well as any graphs and charts, and the page numbers on which they can be found. Executive Summary. The executive summary summarizes all the details in the report in a very quick way. Many people who receive the report—both executives and nonexecutives—won’t have time to read the entire report. Instead, they will rely on the executive summary to quickly get an idea of the study’s results and what to do about those results. Methodology and Limitations. The methodology section of the report explains the technical details of how the research was designed and conducted. The section explains, for example, how the data was collected and by whom, the size of the sample, how it was chosen, and whom or what it consisted of (e.g., the number of women versus men or children versus adults). It also includes information about the statistical techniques used to analyze the data. Every study has errors—sampling errors, interviewer errors, and so forth. The methodology section should explain these details, so decision makers can consider their overall impact. The margin of error A measure of the possible inaccuracy of the data reported in a survey. is the overall tendency of the study to be off kilter—that is, how far it could have gone wrong in either direction. Remember how newscasters present the presidential polls before an election? They always say, “This candidate is ahead 48 to 44 percent, plus or minus 2 percent.” That “plus or minus” is the margin of error. The larger the margin of error is, the less likely the results of the study are accurate. The margin of error needs to be included in the methodology section. Findings. The findings section is a longer, fleshed-out version of the executive summary that goes into more detail about the statistics uncovered by the research that bolster the study’s findings. If you have related research or secondary data on hand that back up the findings, it can be included to help show the study did what it was designed to do. Recommendations. The recommendations section should outline the course of action you think should be taken based on the findings of the research and the purpose of the project. For example, if you conducted a global market research study to identify new locations for stores, make a recommendation for the locations. Sherrie Mersdorf, “How to Organize Your Next Survey Report,” Cvent, August 24, 2009, http://survey.cvent.com/blog/cvent-survey/0/0/how-to-organize-your-next-survey-report (accessed December 14, 2009). As we have said, these are the basic sections of a marketing research report. However, additional sections can be added as needed. For example, you might need to add a section on the competition and each firm’s market share. If you’re trying to decide on different supply chain options, you will need to include a section on that topic. As you write the research report, keep your audience in mind. Don’t use technical jargon decision makers and other people reading the report won’t understand. If technical terms must be used, explain them. Also, proofread the document to ferret out any grammatical errors and typos, and ask a couple of other people to proofread behind you to catch any mistakes you might have missed. If your research report is riddled with errors, its credibility will be undermined, even if the findings and recommendations you make are extremely accurate. Many research reports are presented via PowerPoint. If you’re asked to create a slideshow presentation from the report, don’t try to include every detail in the report on the slides. The information will be too long and tedious for people attending the presentation to read through. And if they do go to the trouble of reading all the information, they probably won’t be listening to the speaker who is making the presentation. Instead of including all the information from the study in the slides, boil each section of the report down to key points and add some “talking points” only the presenter will see. After or during the presentation, you can give the attendees the longer, paper version of the report so they can read the details at a convenient time, if they choose to. Key Takeaway Step 1 in the marketing research process is to define the problem. Businesses take a look at what they believe are symptoms and try to drill down to the potential causes so as to precisely define the problem. The next task for the researcher is to put into writing the research objective, or goal, the research is supposed to accomplish. Step 2 in the process is to design the research. The research design is the “plan of attack.” It outlines what data you are going to gather, from whom, how, and when, and how you’re going to analyze it once it has been obtained. Step 3 is to design the data-collection forms, which need to be standardized so the information gathered on each is comparable. Surveys are a popular way to gather data because they can be easily administered to large numbers of people fairly quickly. However, to produce the best results, survey questionnaires need to be carefully designed and pretested before they are used. Step 4 is drawing the sample, or a subset of potential buyers who are representative of your entire target market. If the sample is not correctly selected, the research will be flawed. Step 5 is to actually collect the data, whether it’s collected by a person face-to-face, over the phone, or with the help of computers or the Internet. The data-collection process is often different in foreign countries. Step 6 is to analyze the data collected for any obvious errors, tabulate the data, and then draw conclusions from it based on the results. The last step in the process, Step 7, is writing the research report and presenting the findings to decision makers.	msmarco_doc_00_12233309
http://2012books.lardbucket.org/books/online-marketing-essentials/s21-03-primary-and-secondary-research.html	Primary and Secondary Research	18.3 Primary and Secondary Research 18.3 Primary and Secondary Research Learning Objective The Internet and Secondary Research The Internet and Primary Research Online Research Communities Listening Labs Discussion Conversion Optimization Key Takeaways Exercise	Primary and Secondary Research 18.3 Primary and Secondary Research Learning Objective Understand how primary and secondary research work. The Internet is a useful tool when conducting both primary research The collection of data to present a new set of findings from original research. and secondary research Collection of existing research data. . Not only are there a number of free tools available when it comes to calculating things such as sample size and confidence levels, but it is also an ideal medium to reach large numbers of people for a relatively low cost. Notably, the origins of the Web as a network for academics to share information make it a useful tool for researching existing research reports. Figure 18.2 Sources of Primary and Secondary Research Data The Internet and Secondary Research Market research based on secondary resources uses data that already exist for analysis. This includes both internal data and external data and is useful for exploring the market and marketing problems that exist. Research based on secondary data should precede primary data research. It should be used in establishing the context and parameters for primary research. Uses of secondary data include the following: The data can provide enough information to solve the problem at hand, thereby negating the need for further research. Secondary data can provide sources for hypotheses that can be explored through primary research. Sifting through secondary data is a necessary precursor for primary research, as it can provide information relevant to sample sizes and audience, for example. The data can be used as a reference base to measure the accuracy of primary research. Companies that transact online have a wealth of data that can be mined that exist due to the nature of the Internet. Every action that is performed on the company Web site is recorded in the server logs for the Web site. Customer communications are also a source of data that can be used, particularly communications with a customer service department. Committed customers who either complain, comment, or compliment are providing information that can form the foundation for researching customer satisfaction. Social networks, blogs, and other forms of social media have emerged as forums where consumers discuss their likes and dislikes, and customers can be particularly vocal about companies and products. These data can, and should, be tracked and monitored to establish consumer sentiment. If a community is established for research purposes, this should be considered primary data, but using social media to research existing sentiments is considered secondary research. The Internet is an ideal starting point for conducting secondary research based on published data and findings. But with so much information out there, it can be a daunting task to find reliable resources. Figure 18.3 Google shows many entries for “research.” The first point of call for research online is usually a search engine, such as http://www.google.com or http://www.yahoo.com. Search engines usually have an array of advanced features that can aid online research. For example, Google offers Advanced Search ( http://www.google.com/advanced_ search?hl=en ), Google Scholar ( http://scholar.google.com ), and Google Book Search ( http://www.google.com/books ). Learning how to use search engines to find the information you need is a valuable skill in using the Internet for research. Many research publications are available online, some for free and some for a fee. Many of the top research companies feature analyst blogs, which provide some industry data and analysis for free. Some notable resources are the following: http://www.e-consultancy.com http://www.jupiterresearch.com http://www.hitwise.com http://www.pewinternet.org (U.S. data) http://www.worldwideworx.com (South African data) The Internet and Primary Research Primary research involves gathering data for a specific research task. It is based on data that have not been gathered beforehand. Primary research can be either qualitative or quantitative. Primary research can be used to explore a market and can help develop the hypotheses or research questions that must be answered by further research. Generally, qualitative data are gathered at this stage. For example, online research communities can be used to identify consumer needs that are not being met and brainstorm possible solutions. Further quantitative research can investigate what proportion of consumers share these problems and which potential solutions best meet those needs. Online Research Communities Although online communities are a valuable resource for secondary research, communities can also provide primary data. General Motors’ Fast Lane blog is an example of an online research community that aids in the gathering of research data. The blog can be used as a means to elicit feedback on a particular research problem. This is qualitative data that can aid the company in exploring its research problem further. Listening Labs When developing Web sites and online applications, usability testing is a vital process that will ensure that the Web site or application is able to meet consumers’ needs. Listening labs involve setting up a testing environment where the use of a Web site or application by a consumer may be observed. Discussion Who would you select to participate in listening lab exercises? How do you think the demographic of your population affects the outcome of these tests? Conversion Optimization Conversion optimization aims to determine the factors of an advertisement, Web site, or Web page that can be improved so as to make the Web site convert best. From PPC (pay-per-click) advertising, to e-mail subject lines, to shopping cart design, tests can be set up to test what variables are affecting the conversion rate of visitors to the Web site. Chapter 15 "Web Analytics and Conversion Optimization" contains details and tools for running tests, such as A/B split testing and multivariate testing. Key Takeaways The Internet is an ideal way to reach a large number of people at a relatively low cost. Market research based on secondary resources uses data that already exist for analysis. Research based on secondary data should precede primary data research. There are four main uses of secondary data: Data can provide enough information to solve the problem at hand, thereby negating the need for further research. Secondary data can provide sources for hypotheses that can be explored through primary research. Sifting through secondary data is a necessary precursor for primary research, as it can provide information relevant to sample sizes and audience. The data can be used as a reference base to measure the accuracy of primary research. Companies that transact online have a wealth of data available to them. Social media have emerged as a forum where consumers discuss their likes and dislikes. Exercise How does the Internet change the role of the researcher when it comes to market research?	msmarco_doc_00_12298548
http://2012books.lardbucket.org/books/policy-and-theory-of-international-economics/s21-10-effect-of-a-price-level-increa.html	Effect of a Price Level Increase (Inflation) on Interest Rates	18.10 Effect of a Price Level Increase (Inflation) on Interest Rates 18.10 Effect of a Price Level Increase (Inflation) on Interest Rates Learning Objective Key Takeaway Exercise	Effect of a Price Level Increase (Inflation) on Interest Rates 18.10 Effect of a Price Level Increase (Inflation) on Interest Rates Learning Objective Learn how a change in the price level affects the equilibrium interest rate. Now let’s consider the effects of a price level increase in the money market. When the price level rises in an economy, the average price of all goods and services sold is increasing. Inflation is calculated as the percentage increase in a country’s price level over some period, usually a year. This means that in the period during which the price level increases, inflation is occurring. Thus studying the effects of a price level increase is the same as studying the effects of inflation. Inflation can arise for several reasons that will be discussed later in this chapter. For now, we will imagine that the price level increases for some unspecified reason and consider the consequences. Suppose the money market is originally in equilibrium at point A in Figure 18.4 "Effects of a Price Level Increase" with real money supply MS / P$ ′ and interest rate i$ ′. Suppose the price level increases, ceteris paribus. Again, the ceteris paribus assumption means that we assume all other exogenous variables in the model remain fixed at their original levels. In this exercise, it means that the money supply ( MS) and real GDP ( Y$) remain fixed. An increase in the price level ( P$) causes a decrease in the real money supply ( MS / P$) since MS remains constant. In the adjoining diagram, this is shown as a shift from MS / P$ ′ to MS / P$ ″. At the original interest rate, i$ ′, the real money supply has fallen to level 2 along the horizontal axis, while real money demand remains at level 1. This means that money demand exceeds money supply and the actual interest rate is lower than the new equilibrium rate. Adjustment to the higher interest rate will follow the “interest rate too low” equilibrium story. Figure 18.4 Effects of a Price Level Increase More intuition concerning these effects arises if one recalls that price level increases will increase the transactions demand for money. In this version, nominal money demand will exceed nominal money supply and set off the same adjustment process described in the previous paragraph. The final equilibrium will occur at point B on the diagram. The real money supply will have fallen from level 1 to level 2 while the equilibrium interest rate has risen from i$ ′ to i$ ″. Thus an increase in the price level (i.e., inflation) will cause an increase in average interest rates in an economy. In contrast, a decrease in the price level (deflation) will cause a decrease in average interest rates in an economy. Key Takeaway An increase in the price level (i.e., inflation), ceteris paribus, will cause an increase in average interest rates in an economy. In contrast, a decrease in the price level (deflation), ceteris paribus, will cause a decrease in average interest rates in an economy. Exercise Jeopardy Questions. As in the popular television game show, you are given an answer to a question and you must respond with the question. For example, if the answer is “a tax on imports,” then the correct question is “What is a tariff?” The term used to describe a percentage increase in a country’s price level over a period of time. Of increase, decrease, or stay the same, the effect on the equilibrium interest rate when the domestic price level decreases, ceteris paribus. Of increase, decrease, or stay the same, the effect on the equilibrium interest rate when the domestic price level increases, ceteris paribus.	msmarco_doc_00_12306180
http://2012books.lardbucket.org/books/policy-and-theory-of-international-finance/s10-11-effect-of-a-real-gdp-increase-.html	Effect of a Real GDP Increase (Economic Growth) on Interest Rates	7.11 Effect of a Real GDP Increase (Economic Growth) on Interest Rates 7.11 Effect of a Real GDP Increase (Economic Growth) on Interest Rates Learning Objective Key Takeaway Exercise	Effect of a Real GDP Increase (Economic Growth) on Interest Rates 7.11 Effect of a Real GDP Increase (Economic Growth) on Interest Rates Learning Objective Learn how a change in real GDP affects the equilibrium interest rate. Finally, let’s consider the effects of an increase in real gross domestic product (GDP). Such an increase represents economic growth. Thus the study of the effects of a real GDP increase is the same as asking how economic growth will affect interest rates. GDP may increase for a variety of reasons, which are discussed in subsequent chapters. For now, we will imagine that GDP increases for some unspecified reason and consider the consequences of such a change in the money market. Suppose the money market is originally in equilibrium at point A in Figure 7.5 "Effects of an Increase in Real GDP" with real money supply MS / P$ and interest rate i$ ′. Suppose real GDP ( Y$) increases, ceteris paribus. Again, the ceteris paribus assumption means that we assume all other exogenous variables in the model remain fixed at their original levels. In this exercise, it means that the money supply ( MS) and the price level ( P$) remain fixed. An increase in GDP will raise the demand for money because people will need more money to make the transactions necessary to purchase the new GDP. In other words, real money demand rises due to the transactions demand effect. This increase is reflected in the rightward shift of the real money demand function from L ( i$, Y$ ′) to L ( i$, Y$ ″). Figure 7.5 Effects of an Increase in Real GDP At the original interest rate, i$′, real money demand has increased to level 2 along the horizontal axis while real money supply remains at level 1. This means that real money demand exceeds real money supply and the current interest rate is lower than the equilibrium rate. Adjustment to the higher interest rate will follow the “interest rate too low” equilibrium story. The final equilibrium will occur at point B on the diagram. As the interest rate rises from i$ ′ to i$ ″, real money demand will have fallen from level 2 to level 1. Thus an increase in real GDP (i.e., economic growth) will cause an increase in average interest rates in an economy. In contrast, a decrease in real GDP (a recession) will cause a decrease in average interest rates in an economy. Key Takeaway An increase in real gross domestic product (i.e., economic growth), ceteris paribus, will cause an increase in average interest rates in an economy. In contrast, a decrease in real GDP (a recession), ceteris paribus, will cause a decrease in average interest rates in an economy. Exercise Jeopardy Questions. As in the popular television game show, you are given an answer to a question and you must respond with the question. For example, if the answer is “a tax on imports,” then the correct question is “What is a tariff?” The term used to describe a percentage increase in real GDP over a period of time. Of increase, decrease, or stay the same, the effect on the equilibrium interest rate when real GDP decreases, ceteris paribus. Of increase, decrease, or stay the same, the effect on the equilibrium interest rate when real GDP increases, ceteris paribus.	msmarco_doc_00_12310349
http://2012books.lardbucket.org/books/policy-and-theory-of-international-finance/s15-02-monetary-policy-with-fixed-exc.html	Monetary Policy with Fixed Exchange Rates	12.2 Monetary Policy with Fixed Exchange Rates 12.2 Monetary Policy with Fixed Exchange Rates Learning Objective Expansionary Monetary Policy Contractionary Monetary Policy Discussion Key Takeaways Exercise	Monetary Policy with Fixed Exchange Rates 12.2 Monetary Policy with Fixed Exchange Rates Learning Objective Learn how changes in monetary policy affect GNP, the value of the exchange rate, and the current account balance in a fixed exchange rate system in the context of the AA-DD model. Understand the adjustment process in the money market, the Forex market, and the G&S market. In this section, we use the AA-DD model to assess the effects of monetary policy in a fixed exchange rate system. Recall from Chapter 7 "Interest Rate Determination" that the money supply is effectively controlled by a country’s central bank. In the case of the United States, this is the Federal Reserve Board, or the Fed. When the money supply increases due to action taken by the central bank, we refer to it as expansionary monetary policy. If the central bank acts to reduce the money supply, it is referred to as contractionary monetary policy. Methods that can be used to change the money supply are discussed in Chapter 7 "Interest Rate Determination", Section 7.5 "Controlling the Money Supply". Expansionary Monetary Policy Suppose the United States fixes its exchange rate to the British pound at the rate Ē$/£. This is indicated in Figure 12.1 "Expansionary Monetary Policy with a Fixed Exchange Rate" as a horizontal line drawn at Ē$/£. Suppose also that the economy is originally at a superequilibrium shown as point F with original gross national product (GNP) level Y1. Next, suppose the U.S. central bank (the Fed) decides to expand the money supply by conducting an open market operation, ceteris paribus. Ceteris paribus means that all other exogenous variables are assumed to remain at their original values. A purchase of Treasury bonds by the Fed will lead to an increase in the dollar money supply. As shown in Chapter 9 "The AA-DD Model", Section 9.5 "Shifting the AA Curve", money supply changes cause a shift in the AA curve. More specifically, an increase in the money supply will cause AA to shift upward (i.e., ↑ MS is an AA up-shifter). This is depicted in the diagram as a shift from the red AA to the blue A ′ A ′ line. Figure 12.1 Expansionary Monetary Policy with a Fixed Exchange Rate The money supply increase puts upward pressure on the exchange rate in the following way. First, a money supply increase causes a reduction in U.S. interest rates. This in turn reduces the rate of return on U.S. assets below the rate of return on similar assets in Britain. Thus international investors will begin to demand more pounds in exchange for dollars on the private Forex to take advantage of the relatively higher RoR of British assets. In a floating exchange system, excess demand for pounds would cause the pound to appreciate and the dollar to depreciate. In other words, the exchange rate E$/£ would rise. In the diagram, this would correspond to a movement to the new A′A′ curve at point G. However, because the country maintains a fixed exchange rate, excess demand for pounds on the private Forex will automatically be relieved by Fed intervention. The Fed will supply the excess pounds demanded by selling reserves of pounds in exchange for dollars at the fixed exchange rate. As we showed in Chapter 10 "Policy Effects with Floating Exchange Rates", Section 10.5 "Foreign Exchange Interventions with Floating Exchange Rates", Fed sales of foreign currency result in a reduction in the U.S. money supply. This is because when the Fed buys dollars in the private Forex, it is taking those dollars out of circulation and thus out of the money supply. Since a reduction of the money supply causes AA to shift back down, the final effect will be that the AA curve returns to its original position. This is shown as the up and down movement of the AA curve in the diagram. The final equilibrium is the same as the original at point F. The AA curve must return to the same original position because the exchange rate must remain fixed at Ē$/£. This implies that the money supply reduction due to Forex intervention will exactly offset the money supply expansion induced by the original open market operation. Thus the money supply will temporarily rise but then will fall back to its original level. Maintaining the money supply at the same level also assures that interest rate parity is maintained. Recall that in a fixed exchange rate system, interest rate parity requires equalization of interest rates between countries (i.e., i$ = i£ ). If the money supply did not return to the same level, interest rates would not be equalized. Thus after final adjustment occurs, there are no effects from expansionary monetary policy in a fixed exchange rate system. The exchange rate will not change and there will be no effect on equilibrium GNP. Also, since the economy returns to the original equilibrium, there is also no effect on the current account balance. Contractionary Monetary Policy Contractionary monetary policy corresponds to a decrease in the money supply or a Fed sale of Treasury bonds on the open bond market. In the AA-DD model, a decrease in the money supply shifts the AA curve downward. The effects will be the opposite of those described above for expansionary monetary policy. A complete description is left for the reader as an exercise. The quick effects, however, are as follows. U.S. contractionary monetary policy with a fixed exchange rate will have no effects within the economy. E$/£, Y$ and the current account balance will all be maintained or return to their initial levels. Discussion This result indicates that monetary policy is ineffective in influencing the economy in a fixed exchange rate system. In contrast, in a floating exchange rate system, monetary policy can either raise or lower GNP, at least in the short run. Thus monetary policy has some effectiveness in a floating system, and central bank authorities can adjust policy to affect macroeconomic conditions within their economy. For example, if the economy is growing only sluggishly, or perhaps is contracting, the central bank can raise the money supply to help spur an expansion of GNP, if the economy has a floating exchange rate. However, with a fixed exchange rate, the central bank no longer has this ability. This explains why countries lose monetary autonomy (or independence) with a fixed exchange rate. The central bank can no longer have any influence over the interest rate, exchange rate, or the level of GNP. One other important comparison worth making is between expansionary monetary policy in a fixed exchange rate system with sterilized foreign exchange (Forex) interventions in a floating system. In the first case, expansionary monetary policy is offset later with a contraction of the money supply caused by automatic Forex intervention. In the second case, Forex intervention leading to an expansion of the money supply is countered with contractionary open market operations. In the first case, the interest rate is maintained to satisfy interest rate parity. In the second case, the interest rate remains fixed by design. Clearly, these two situations represent exactly the same set of actions, though in a different order. Thus it makes sense that the two policies would have the same implications—that is, “no impact” on any of the economic variables. Key Takeaways There are no effects from expansionary or contractionary monetary policy in a fixed exchange rate system. The exchange rate will not change, there will be no effect on equilibrium GNP, and there will be no effect on the current account balance. Monetary policy in a fixed exchange rate system is equivalent in its effects to sterilized Forex interventions in a floating exchange rate system. Exercise Suppose that Latvia can be described with the AA-DD model and that Latvia fixes its currency, the lats (Ls), to the euro. Consider the changes in the exogenous variable in the left column. Indicate the short-run effects on the equilibrium levels of Latvian GNP, the Latvian interest rate ( iLs) , the Latvian trade balance, and the exchange rate ( ELs/€ ). Use the following notation: + the variable increases − the variable decreases 0 the variable does not change A the variable change is ambiguous (i.e., it may rise, it may fall) GNP iLs Trade Balance ELs/€ An increase in the Latvian money supply A decrease in the Latvian money supply	msmarco_doc_00_12314106