2304. Chapter 21 -
1. There are several sets of answers; one is:
(a) $\mathrm{C}_{5} \mathrm{H}_{12}$

(b) $\mathrm{C}_{5} \mathrm{H}_{10}$

(c) $\mathrm{C}_{5} \mathrm{H}_{8}$

2. Both reactions result in bromine being incorporated into the structure of the product. The difference is the way in which that incorporation takes place. In the saturated hydrocarbon, an existing $\mathrm{C}-\mathrm{H}$ bond is broken, and a bond between the C and the Br can then be formed. In the unsaturated hydrocarbon, the only bond broken in the hydrocarbon is the $\pi$ bond whose electrons can be used to form a bond to one of the bromine atoms in $\mathrm{Br}_{2}$ (the electrons from the $\mathrm{Br}-\mathrm{Br}$ bond form the other $\mathrm{C}-\mathrm{Br}$ bond on the other carbon that was part of the $\pi$ bond in the starting unsaturated hydrocarbon).
3. Unbranched alkanes have free rotation about the $\mathrm{C}-\mathrm{C}$ bonds, yielding all orientations of the substituents about these bonds equivalent, interchangeable by rotation. In the unbranched alkenes, the inability to rotate about the $\mathrm{C}=\mathrm{C}$ bond results in fixed (unchanging) substituent orientations, thus permitting different isomers. Since these concepts pertain to phenomena at the molecular level, this explanation involves the microscopic domain.
4. They are the same compound because each is a saturated hydrocarbon containing an unbranched chain of six carbon atoms.
5. (a) $\mathrm{C}_{6} \mathrm{H}_{14}$

(b) $\mathrm{C}_{6} \mathrm{H}_{14}$

(c) $\mathrm{C}_{6} \mathrm{H}_{12}$

(d) $\mathrm{C}_{6} \mathrm{H}_{12}$

(e) $\mathrm{C}_{6} \mathrm{H}_{10}$

(f) $\mathrm{C}_{6} \mathrm{H}_{10}$


2304. Chapter 21 -
(e) $\mathrm{C}_{6} \mathrm{H}_{10}$

(f) $\mathrm{C}_{6} \mathrm{H}_{10}$

6. (a) 2,2-dibromobutane; (b) 2-chloro-2-methylpropane; (c) 2-methylbutane; (d) 1-butyne; (e) 4-fluoro-4-methyl-1-octyne; (f) trans-1-chloropropene; (g) 4-methyl-1-pentene
7.

n-butane

2-methylpropane
15.

cis-

trans-
17. (a) 2,2,4-trimethylpentane; (b) 2,2,3-trimethylpentane, 2,3,4-trimethylpentane, and 2,3,3-trimethylpentane:

19.

1-chlorobutane

2-chlorobutane

2-chloro-2-methylpropane

1-chloro-2-methylpropane (1-chloro-2-methylpropane)
21. In the following, the carbon backbone and the appropriate number of hydrogen atoms are shown in condensed form:

23.

In acetylene, the bonding uses $s p$ hybrids on carbon atoms and $s$ orbitals on hydrogen atoms. In benzene, the carbon atoms are $s p^{2}$ hybridized.
25. (a) $\mathrm{CH} \equiv \mathrm{CCH}_{2} \mathrm{CH}_{3}+2 \mathrm{I}_{2} \longrightarrow \mathrm{CHI}_{2} \mathrm{CI}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}$

(b) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}+8 \mathrm{O}_{2} \longrightarrow 5 \mathrm{CO}_{2}+6 \mathrm{H}_{2} \mathrm{O}$


2304. Chapter 21 -
27. 65.2 g
29. $9.328 \times 10^{2} \mathrm{~kg}$
31. (a) ethyl alcohol, ethanol: $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}$; (b) methyl alcohol, methanol: $\mathrm{CH}_{3} \mathrm{OH}$; (c) ethylene glycol, ethanediol: $\mathrm{HOCH}_{2} \mathrm{CH}_{2} \mathrm{OH}$; (d) isopropyl alcohol, 2-propanol: $\mathrm{CH}_{3} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{3}$; (e) glycerine, 1,2,3-trihydroxypropane: $\mathrm{HOCH}_{2} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{2} \mathrm{OH}$
33. (a) 1-ethoxybutane, butyl ethyl ether; (b) 1-ethoxypropane, ethyl propyl ether; (c) 1-methoxypropane, methyl propyl ether
35. $\mathrm{HOCH}_{2} \mathrm{CH}_{2} \mathrm{OH}$, two alcohol groups; $\mathrm{CH}_{3} \mathrm{OCH}_{2} \mathrm{OH}$, ether and alcohol groups
37. (a)

(b) $4.593 \times 10^{2} \mathrm{~L}$
39. (a) $\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCH}_{3}+\mathrm{H}_{2} \mathrm{O} \longrightarrow \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{3}$

(b) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH} \longrightarrow \mathrm{CH}_{2}=\mathrm{CH}_{2}+\mathrm{H}_{2} \mathrm{O}$

41. (a)

(b)

(c)


2304. Chapter 21 -
41. (a)

(b)

(c)

43. A ketone contains a group bonded to two additional carbon atoms; thus, a minimum of three carbon atoms are needed.
45. Since they are both carboxylic acids, they each contain the -COOH functional group and its characteristics. The difference is the hydrocarbon chain in a saturated fatty acid contains no double or triple bonds, whereas the hydrocarbon chain in an unsaturated fatty acid contains one or more multiple bonds.
47. (a) $\mathrm{CH}_{3} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{3}$ : all carbons are tetrahedral; (b) $\mathrm{CH}_{3} \mathrm{COCH}_{3}$ : the end carbons are tetrahedral and the central carbon is trigonal planar; (c) $\mathrm{CH}_{3} \mathrm{OCH}_{3}$ : all are tetrahedral; (d) $\mathrm{CH}_{3} \mathrm{COOH}$ : the methyl carbon is tetrahedral and the acid carbon is trigonal planar; (e) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}\left(\mathrm{CH}_{3}\right) \mathrm{CHCH}_{2}$ : all are tetrahedral except the right-most two carbons, which are trigonal planar
49.

51. (a) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}+\mathrm{CH}_{3} \mathrm{C}(\mathrm{O}) \mathrm{OH} \longrightarrow \mathrm{CH}_{3} \mathrm{C}(\mathrm{O}) \mathrm{OCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}+\mathrm{H}_{2} \mathrm{O}$ :


2304. Chapter 21 -
(b) $2 \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH}+\mathrm{CaCO}_{3} \longrightarrow\left(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COO}\right)_{2} \mathrm{Ca}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O}$ :

53.

Compound A

Compound $B$

Compound C
55. Trimethyl amine: trigonal pyramidal, $s p^{3}$; trimethyl ammonium ion: tetrahedral, $s p^{3}$
57.

pyridine,
trigonal planar, $s p^{2}$
(nonlinear or bent)
pyridinium ion, trigonal planar, $s p^{2}$
(trigonal planar)
59. $\mathrm{CH}_{3} \mathrm{NH}_{2}+\mathrm{H}_{3} \mathrm{O}^{+} \longrightarrow \mathrm{CH}_{3} \mathrm{NH}_{3}{ }^{+}+\mathrm{H}_{2} \mathrm{O}$

61. $\mathrm{CH}_{3} \underline{\mathrm{C}} \mathrm{H}=\mathrm{CHCH}_{3}\left(s p^{2}\right)+\mathrm{Cl} \longrightarrow \mathrm{CH}_{3} \underline{\mathrm{CH}}(\mathrm{Cl}) \mathrm{H}(\mathrm{Cl}) \mathrm{CH}_{3}\left(s p^{3}\right) ; 2 \underline{\mathrm{C}}_{6} \mathrm{H}_{6}\left(s p^{2}\right)+15 \mathrm{O}_{2} \longrightarrow 12 \underline{\mathrm{CO}}_{2}(s p)+6 \mathrm{H}_{2} \mathrm{O}$
63. The carbon in $\mathrm{CO}_{3}{ }^{2-}$, initially at $s p^{2}$, changes hybridization to $s p$ in $\mathrm{CO}_{2}$.


2304. Chapter 21 -
Ernest Rutherford, "The Development of the Theory of Atomic Structure," ed. J. A. Ratcliffe, in Background to Modern Science, eds. Joseph Needham and Walter Pagel, (Cambridge, UK: Cambridge University Press, 1938), 61-74. Accessed September 22, 2014, https://ia600508.us.archive.org/3/items/backgroundtomode032734mbp/backgroundtomode032734mbp.pdf.

Omiatek, Donna M., Amanda J. Bressler, Ann-Sofie Cans, Anne M. Andrews, Michael L. Heien, and Andrew G. Ewing. "The Real Catecholamine Content of Secretory Vesicles in the CNS Revealed by Electrochemical Cytometry." Scientific Report 3 (2013): 1447, accessed January 14, 2015, doi:10.1038/srep01447.

Per the IUPAC definition, group 12 elements are not transition metals, though they are often referred to as such. Additional details on this group's elements are provided in a chapter on transition metals and coordination chemistry.

Note that orbitals may sometimes be drawn in an elongated "balloon" shape rather than in a more realistic "plump" shape in order to make the geometry easier to visualize.

The IUPAC definition of standard pressure was changed from 1 atm to $1 \mathrm{bar}(100 \mathrm{kPa})$ in 1982, but the prior definition remains in use by many literature resources and will be used in this text.

"Quotations by Joseph-Louis Lagrange," last modified February 2006, accessed February 10, 2015, http://www-history.mcs.standrews.ac.uk/Quotations/Lagrange.html

US Energy Information Administration, Primary Energy Consumption by Source and Sector, 2012, http://www.eia.gov/totalenergy/ data/monthly/pdf/flow/css_2012_energy.pdf. Data derived from US Energy Information Administration, Monthly Energy Review (January 2014).


2304. Chapter 21 -
Francis D. Reardon et al. "The Snellen human calorimeter revisited, re-engineered and upgraded: Design and performance characteristics." Medical and Biological Engineering and Computing 8 (2006)721-28, http://link.springer.com/article/10.1007/ s11517-006-0086-5.

This question is taken from the Chemistry Advanced Placement Examination and is used with the permission of the Educational Testing Service.

Titration of 25.00 mL of $0.100 \mathrm{M} \mathrm{HCl}(0.00250 \mathrm{~mol}$ of HCI$)$ with 0.100 M NaOH .
2 Titration of 25.00 mL of $0.100 \mathrm{MCH}_{3} \mathrm{CO}_{2} \mathrm{H}\left(0.00250 \mathrm{~mol}\right.$ of $\left.\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{H}\right)$ with 0.100 M NaOH .

Herrlich, P. "The Responsibility of the Scientist: What Can History Teach Us About How Scientists Should Handle Research That Has the Potential to Create Harm?" EMBO Reports 14 (2013): 759-764.

"The Nobel Prize in Chemistry 1995," Nobel Prize.org, accessed February 18, 2015, http://www.nobelprize.org/nobel_prizes/ chemistry/laureates/1995/.

The " m " in Tc-99m stands for "metastable," indicating that this is an unstable, high-energy state of Tc-99. Metastable isotopes emit $\gamma$ radiation to rid themselves of excess energy and become (more) stable.

This is the Beilstein database, now available through the Reaxys site (www.elsevier.com/online-tools/reaxys).
2 Peplow, Mark. "Organic Synthesis: The Robo-Chemist," Nature 512 (2014): 20-2.

Physical properties for $\mathrm{C}_{4} \mathrm{H}_{10}$ and heavier molecules are those of the normal isomer, $n$-butane, $n$-pentane, etc.


2304. Chapter 21 -
Physical properties for $\mathrm{C}_{4} \mathrm{H}_{10}$ and heavier molecules are those of the normal isomer, $n$-butane, $n$-pentane, etc.

STP indicates a temperature of $0^{\circ} \mathrm{C}$ and a pressure of 1 atm .

The IUPAC adopted new nomenclature guidelines in 2013 that require this number to be placed as an "infix" rather than a prefix. For example, the new name for 2-propanol would be propan-2-ol. Widespread adoption of this new nomenclature will take some time, and students are encouraged to be familiar with both the old and new naming protocols.

Acids and bases are commercially available as aqueous solutions. This table lists properties (densities and concentrations) of common acid and base solutions. Nominal values are provided in cases where the manufacturer cites a range of concentrations and densities.
2 This column contains specific gravity data. In the case of this table, specific gravity is the ratio of density of a substance to the density of pure water at the same conditions. Specific gravity is often cited on commercial labels.
3 This solution is sometimes called "ammonium hydroxide," although this term is not chemically accurate.

\mathrm{y}=$ years, $\mathrm{d}=$ days, $\mathrm{h}=$ hours, $\mathrm{m}=$ minutes, $\mathrm{s}=$ seconds