context
stringlengths 545
71.9k
| questionsrc
stringlengths 16
10.2k
| question
stringlengths 11
563
|
|---|---|---|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 .
|
what is chp and bcop pressure ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ?
|
where on the diagram of the heart does the electrical system fit in ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart .
|
in the last paragraph , what would happen if one pump stops working , will the other be able to help or will that body perish ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well .
|
what if we increase amount of o2 floating in our system ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another .
|
would a human being die from the lack of oxygen in their body ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off .
|
approximately how much oxygen ( in percentage ) would it take for a human being to die/immobilize ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ?
|
which ventricle pumps high pressure ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) .
|
is haemoglobin the plural word of haemoglobin or it is a spelling mistake ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue .
|
why is there still a remaining 3 % of oxygen unattached to proteins in the rbc ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) .
|
can a person fluctuate from hypertension to hypotension ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) .
|
whn finding a pulse the larger arteries have higher pressure but why do the veins have a weaker pressure ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 .
|
if the heart were to go at 140 mmhg but at the flip note , the capillaries are able to hold that amount of pressure and still keep going then can we still survive ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ?
|
what would happen if a machine replaced the heart ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ?
|
would the heart still function properly ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ?
|
what if we got just one ventricle , but the order is heart - > body - > lung - > heart ( lung before heart instead of after heart ) ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood .
|
how long does a red blood cell stay in the lung on average ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ?
|
does the lung empty / fill up with each heart beat , or would your average rbc stay in the lungs/alveoli for longer ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 .
|
if the reason human hearts have 2 ventricles is to get the pressure right , are there other hearts that have 1 ventricle ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ?
|
would n't also another reason the heart has two pumps is for the heart to get oxygen itself so it can work ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle .
|
when oxygen diffuses from alveoli to blood vessels , is there any chance of oxygen producing air bubbles in the blood ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs .
|
how does the heart suck in blood and air ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood .
|
is the vein blue or red on the diagram ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool .
|
what are p waves and how do they work ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ?
|
what does the right ventricle do ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 .
|
so when we measure blood pressure it is that left and right ventricular blood pressure ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) .
|
veins carry blood to the heart , arteries carry blood away from the heart , but what does a capillary do exactly ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ?
|
wen a heart attack happens , is it a problem with the bran or the heart ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen .
|
i would n't guess that human blood is ever actually blue , but is there a noticeable color difference between oxygen rich and the otherwise oxygen-less ?
|
the heart is a double pump what cells need to understand the critical importance of the heart requires taking a step back so we understand the needs of each cell in our body . remember that our body is composed of over 10 trillion cells that work together in remarkable unity ( a lesson in good governance ! ) . cells have basic needs , and at the top of the list would be these four things : 1 ) access to oxygen 2 ) a source of glucose 3 ) a balanced fluid environment with the right amount of water/electrolytes 4 ) removal of waste ( such as carbon dioxide ) consider how this compares to basic human needs : breathing air in and breathing out , eating food , drinking water , and getting rid of urine/stool . when you really stop and think about it , many of the things that we do can be traced back to our cellular needs . a breath of air now let ’ s follow a single breath of air . 21 % of the molecules in this breath are oxygen molecules , and as they race down into the lungs , they end up in the alveoli which are tiny air-filled sacs . the story could end there , if not for the remarkable nature of lungs . the lungs allow the oxygen molecules to continue their journey from the gas phase into a new liquid phase . meanwhile carbon dioxide molecules make the opposite trip from liquid to gas similar to what happens at the surface of a carbonated beverage . the oxygen diffuses ( think of the drop of ink in a pool of water ) into the fluid interstitial space of the lung , and is then absorbed into the blood stream , and then enters into the red blood cells themselves . this diffusion occurs in a fraction of a second because the distance between the alveoli and the red blood cell is so tiny . why you need your heart now let ’ s pause and ponder the following : what would happen if there was no heart ? well , diffusion of oxygen works wonders when the distances are very small , but what about large distances like the distance from your lungs to your feet ? could a single molecule of oxygen simply diffuse all the way there ? in theory , it could—but it would take a really long time ! by the time the oxygen arrived in your toes by simple diffusion , they would have died and fallen off . once the oxygen has gotten into the blood stream , there has to be a way to rapidly “ move ” the oxygen molecules from one place to another . this is where hemoglobin , a protein that uses iron to help bind to o2 molecules , comes to the rescue . each red blood cell is filled with ~250 million hemoglobin proteins , and each hemoglobin protein can bind to 4 o2 molecules ( the bound form is called “ oxyhemoglobin ” ) . that means that each red blood cell can bind ~1 billion oxygen molecules ! as a result , the vast majority ( & gt ; 97 % ) of the o2 molecules are actually bound to oxyhemoglobin ; with only a minority of o2 molecules floating freely in the blood . while air is going in and out of the lungs , the heart is busy working as well . blood enters the heart through the superior and inferior vena cava , which are the large veins that bring blood back from the top and bottom of the body respectively . then , the blood remains in the right atrium , which can be thought of as a waiting room for the right ventricle . the right ventricle ( pump # 1 ) has muscular walls that squeeze down and softly push the blood into the arteries , arterioles , and capillaries of the lungs . next , the oxygen diffuses from an area of high concentration ( alveoli ) to an area of low concentration ( blood ) , before the blood returns ( through pulmonary veins ) to the left of the heart . just like the right atrium , the left atrium can be thought of as a waiting room for the left ventricle . the left ventricle is a room with even stronger , thicker , and more muscular walls than the right ventricle . as a result , the left ventricle ( pump # 2 ) forcefully pushes the blood through the arteries and capillaries of the body to get to the trillions of cells in need of oxygen . for the return trip , blood travels through the veins of the body to get back to the right side of the heart and repeat the process . so there you have it – one heart – two pumps : the right ventricle and the left ventricle . why are there two ventricles ? now here ’ s a thought experiment : why not just have just one ventricle ( single pump ) that moves blood to the lungs and then onwards to the rest of the body ? it ’ s actually a great question , since at first glance it seems like it would be more efficient to just allow the blood to go out to the body instead of taking a return trip to the heart . think of it this way using numbers . pressure is needed to move blood through the resistance of a large network of blood vessels like arteries , capillaries , and veins . even if the right ventricle squeezes down and raises the pressure of the blood to about 25mmhg , after passing through the lungs , the blood pressure is back down to about 5mmhg ( a reduction of 20mmhg ) . it goes into the left ventricle where it gets a second squeeze causing the pressure to rise back up to about 120mmhg ( almost 5 times the pulmonary pressure ! ) . that ’ s enough pressure to make it through all of the organs in the body . getting the pressure right now , let ’ s say that the right ventricle raised the pressure up to 140mmhg , then you may be able to have the blood pressure drop 20mmhg and still be at 120mmhg . that sounds like a great solution , except for the fact : 1 . if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen . having lower pressures in the pulmonary circulation is particularly important given the large amount of o2 that needs to diffuse across from the alveoli to the capillaries—every extra millisecond helps ! that ’ s why the human body needs two pumps working at different pressures , high pressure to allow the blood to circulate around the body , and low pressure to allow for optimal gas exchange in the lungs without broken capillaries !
|
if exposed to those high pressures , fluid would get pushed right out of the capillaries and into the lungs ( some capillaries would actually break ! ) , and 2.at high pressures , blood would move past the alveoli so quickly that o2 molecules would n't have time to diffuse into the blood and bind to hemoglobin . this makes sense when you remember that none of the capillaries in the body are exposed to extremely high pressures ( 120-140mmhg ) , because by the time blood gets down to the capillaries it has already passed through arteries ( and arterioles ) , and the pressure has dramatically fallen .
|
if i were to unfortunately cut an artery , and disregarding the blood spurts echoing a heart beat , would i be able to know based on the color ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
how do we determine the slow or fast step ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step .
|
how do we decide whether a reaction is slow or fast ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ?
|
hi , i have some questions : 1- how we can determine the intermediate ( elementary reactions ) for our overall reaction ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism .
|
now , how we can derive intermediate reactions ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
what is the overall reaction ? 2 . what is the rate determining step ?
|
2- is there any way , for example fixing some parameters and varying the other one to derive the leaching mechanism ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions .
|
if a + 2b > c is a third order reaction does it have to be rate = k { a } [ b ] squared ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions .
|
if b is mor influential on rate than a ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
can you use the subscripts of the element as an exponent in the rate law for the slow step ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide .
|
how do you know which elementary steps are slow and fast ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step .
|
in the introduction , why did we predict the rate law as being first order for both no2 and co ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step .
|
is there a way in which you can figure out the elementary steps of a reaction from a given final reaction ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step .
|
how do you find the total order of the reaction ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide .
|
do you just add the orders of the reactants ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step .
|
how to check whether the given elementary reaction is fast or slow ?
|
key points the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step . introduction : rate law and reaction mechanisms one of the most useful applications of kinetics is the ability to use reaction rates to figure out the reaction mechanism . the reaction mechanism describes the sequence of elementary steps that occur to go from reactants to products . let 's start by considering the following reaction between nitrogen dioxide and carbon monoxide : $ \text { no } _2 ( g ) + \text { co } ( g ) \rightarrow \text { no } ( g ) + \text { co } _2 ( g ) $ based on the balanced reaction , we might hypothesize this reaction might occur from a single collision between a molecule of nitrogen dioxide and a molecule of carbon monoxide . in other words , we hypothesize this an elementary reaction . in that case , we can use the stoichiometry of the balanced chemical reaction to predict the rate law is first order in $ \text { no } _2 $ and first order in $ \text { co } $ . to test our hypothesis , we run some kinetics experiments to get the following rate law : $ \text { rate } = k [ \text { no } _2 ] ^2 $ since the experimental rate law does not match our predicted rate law , we know immediately that our reaction must involve more than one step . reactions that involve more than one elementary step are called complex reactions . we can use the rate law to get additional information about the individual steps that might be involved in the reaction mechanism . reaction mechanisms and the rate law a complex reaction is a little like building a car on an assembly line , where each assembly step is a molecular collision . each collision can result in the breaking and/or making of one or more chemical bonds . chemists can come up with a hypothetical reaction mechanism based on the experimentally determined rate law , as well as chemical intuition . at a minimum , the elementary reactions that make up the proposed reaction mechanism must sum to the overall reaction . in this article , we will learn how to analyze a reaction mechanism using kinetics ( and maybe just a bit of chemical intuition ) . mechanism example and reaction intermediates now that we know the reaction between nitrogen dioxide and carbon monoxide is not an elementary reaction , we can try to come up with alternative mechanisms , such as the following two-step reaction : $ \begin { align } \cancel { 2 } \text { no } _2 ( g ) \quad\quad\quad & amp ; \xrightarrow { slow } \text { no } ( g ) + \cancel { \text { no } _3 } ( g ) \quad { \text { elementary step 1 } } \ \ \cancel { \text { no } _3 } ( g ) +\text { co } ( g ) & amp ; \xrightarrow { fast } \cancel { \text { no } _2 } ( g ) +\text { co } _2 ( g ) \quad { \text { elementary step 2 } } \\hline \ \ \text { no } _2 ( g ) + \text { co } ( g ) & amp ; \xrightarrow { } \text { no } ( g ) + \text { co } _2 ( g ) \quad\quad~~ { \text { overall reaction } } \end { align } $ notice that the elementary steps add up to the overall reaction . this should always be true ! in fact , one of the easiest ways to rule out a proposed reaction mechanism is to show that the elementary steps do n't add up to the overall reaction . the first elementary step produces one of our products , $ \text { no } ( g ) $ , as well as a new species $ \text { no } _3 ( g ) $ . $ \text { no } _3 ( g ) $ is a reaction intermediate . intermediates are produced in one step and consumed in later step , so they do not appear in the overall reaction equation or overall rate law . the rate determining step besides ensuring that the elementary reactions in our reaction mechanism add up to the overall reaction equation , we also consider the rates of each elementary step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step . therefore , we would expect the overall rate to be similar to the rate of the rate of the $ \text { no } _2 $ reacting in elementary step 1 . concept check : what would happen to the reaction rate if we added a catalyst that increased the rate of elementary step 2 by 10x ? another way to visualize this is by thinking about pouring water into a series of funnels with different diameters . the smallest diameter funnel controls the rate at which the bottle is filled , whether it is the first or the last in the series . pouring liquid into the first funnel faster than it can drain through the smallest funnel will only result in an overflow ! practice : analyzing a mechanism let 's consider the proposed reaction mechanism below : $ \begin { align } 2\text { no } & amp ; \xrightarrow { fast } { \text { n } _2\text { o } _2 } \quad\quad\quad\quad { \text { elementary step 1 } } \ \ { \text { n } _2\text { o } _2 } +\text { h } _2 & amp ; \xrightarrow { slow } { \text { n } _2\text { o } } +\text { h } _2\text { o } ~\quad { \text { elementary step 2 } } \ \ { \text { n } _2\text { o } } +\text { h } _2 & amp ; \xrightarrow { fast } \text { n } _2+\text { h } _2\text { o } \quad\quad { \text { elementary step 3 } } \end { align } $ based on this information , try answering the following questions . 1 . what is the overall reaction ? 2 . what is the rate determining step ? 3 . what are the intermediates in this reaction ? how do we evaluate a reaction mechanism ? when evaluating a proposed reaction mechanism , there are two things to check : the elementary reaction equations add up to the overall reaction . the rate law for the overall reaction is consistent with the rate of each elementary step . once we have one or more possible mechanisms that fit the above criteria , we can check if they are supported by further experimental data . for example , if there is an intermediate in our proposed mechanism , we might try detect the intermediate in a reaction mixture . it is important to remember that not being able to observe an expected intermediate does n't necessarily rule out the mechanism , since the intermediate may be present in concentrations that are too low to detect . summary the reaction mechanism describes the sequence of elementary reactions that must occur to go from reactants to products . reaction intermediates are formed in one step and then consumed in a later step of the reaction mechanism . the slowest step in the mechanism is called the rate determining step or rate-limiting step . the overall reaction rate is determined by the rates of the steps up to ( and including ) the rate-determining step .
|
the overall reaction rate is determined by the rates of the steps up to ( and including ) the slowest elementary step . the slowest step in a reaction mechanism is called the rate determining or rate limiting step . for our example mechanism in the previous section , the rate limiting step is the first elementary step .
|
does the overall reaction rate always have to be equal to the slow step ?
|
overview the indian reservation system was created to keep native americans off of lands that european americans wished to settle . the reservation system allowed indian tribes to govern themselves and to maintain some of their cultural and social traditions . the dawes act of 1887 destroyed the reservation system by subdividing tribal lands into individual plots . from removal to the reservation from the earliest days of european colonization , bloody clashes over land and natural resources plagued relations between white settlers and native american indians . european settlers used a variety of methods to wrest land away from native inhabitants , from the negotiation of treaties to forcible removal to declarations of war. $ ^1 $ as white settlers pushed ever further westward across the american continent , these brutal conflicts over land became more frequent and more problematic for the us government . in 1824 , the office of indian affairs was created in order to resolve the land issue . the position of commissioner of indian affairs was established by an act of congress in 1832 , and in 1869 , ely samuel parker became the first native american to be appointed to the position . the office of indian affairs was renamed the bureau of indian affairs in 1947. $ ^2 $ the indian removal act of 1830 institutionalized the practice of forcing native american indians off of their ancestral lands in order to make way for european settlement . the five civilized tribes ( cherokee , chickasaw , choctaw , creek , and seminole ) were forcibly relocated to territories that would become the states of kansas , nebraska , and oklahoma , in a mass migration that became known as the trail of tears . the indian appropriations act of 1851 , also known as the appropriation bill for indian affairs , authorized the establishment of indian reservations in oklahoma and inspired the creation of reservations in other states as well . the us federal government envisioned the reservations as a useful means of keeping native american tribes off of the lands that white americans wished to settle. $ ^3 $ on the reservation many native americans resisted the imposition of the reservation system , sparking a series of conflicts known as the indian wars . through a series of bloody massacres and victories in battle , the us army ultimately succeeded in relocating most indian tribes onto the reservations . the surrounding land and natural resources of the west were thereby opened up to white settlers. $ ^4 $ for most native americans , life on the reservation was difficult . although tribes were allowed to form their own tribal councils and courts , and thus retain their traditional governing structures , indians on the reservations suffered from poverty , malnutrition , and very low standards of living and rates of economic development. $ ^5 $ in 1868 , president ulysses s. grant adopted a policy aimed at assimilating native american indians into mainstream us society . government officials who oversaw indian affairs were replaced with christian clergy in order to convert indians to christianity . this policy led to violent resistance on the part of many native american tribes and was ultimately abandoned under president rutherford b. hayes. $ ^6 $ the destruction and resurrection of the reservation system in 1887 , the us congress passed the dawes act , which ended the reservation system by authorizing the federal confiscation and redistribution of tribal lands . the aim of the act was to destroy tribal governing councils and assimilate native americans into mainstream us society by replacing their communal traditions with a culture centered on the individual . to this end , tribal lands were parceled out into individual allotments , and only those indians who accepted the individual plots were allowed to become us citizens. $ ^7 $ in the 1930s , during the great depression , president franklin d. roosevelt encouraged the passage of the us indian reorganization act , which instituted a “ new deal ” for native americans , authorizing them to reorganize and form their own tribal governments . the act ended the land allotments created by dawes act and thereby resurrected the reservation system , which remains in place today. $ ^8 $ what do you think ? why was the reservation system initially implemented ? what do you see as the most significant cultural differences between native americans and european americans ? do you think life was better for native americans on the reservation or on individual plots of land ? why ?
|
the act ended the land allotments created by dawes act and thereby resurrected the reservation system , which remains in place today. $ ^8 $ what do you think ? why was the reservation system initially implemented ? what do you see as the most significant cultural differences between native americans and european americans ?
|
why was the reservation system initially implemented ?
|
overview the indian reservation system was created to keep native americans off of lands that european americans wished to settle . the reservation system allowed indian tribes to govern themselves and to maintain some of their cultural and social traditions . the dawes act of 1887 destroyed the reservation system by subdividing tribal lands into individual plots . from removal to the reservation from the earliest days of european colonization , bloody clashes over land and natural resources plagued relations between white settlers and native american indians . european settlers used a variety of methods to wrest land away from native inhabitants , from the negotiation of treaties to forcible removal to declarations of war. $ ^1 $ as white settlers pushed ever further westward across the american continent , these brutal conflicts over land became more frequent and more problematic for the us government . in 1824 , the office of indian affairs was created in order to resolve the land issue . the position of commissioner of indian affairs was established by an act of congress in 1832 , and in 1869 , ely samuel parker became the first native american to be appointed to the position . the office of indian affairs was renamed the bureau of indian affairs in 1947. $ ^2 $ the indian removal act of 1830 institutionalized the practice of forcing native american indians off of their ancestral lands in order to make way for european settlement . the five civilized tribes ( cherokee , chickasaw , choctaw , creek , and seminole ) were forcibly relocated to territories that would become the states of kansas , nebraska , and oklahoma , in a mass migration that became known as the trail of tears . the indian appropriations act of 1851 , also known as the appropriation bill for indian affairs , authorized the establishment of indian reservations in oklahoma and inspired the creation of reservations in other states as well . the us federal government envisioned the reservations as a useful means of keeping native american tribes off of the lands that white americans wished to settle. $ ^3 $ on the reservation many native americans resisted the imposition of the reservation system , sparking a series of conflicts known as the indian wars . through a series of bloody massacres and victories in battle , the us army ultimately succeeded in relocating most indian tribes onto the reservations . the surrounding land and natural resources of the west were thereby opened up to white settlers. $ ^4 $ for most native americans , life on the reservation was difficult . although tribes were allowed to form their own tribal councils and courts , and thus retain their traditional governing structures , indians on the reservations suffered from poverty , malnutrition , and very low standards of living and rates of economic development. $ ^5 $ in 1868 , president ulysses s. grant adopted a policy aimed at assimilating native american indians into mainstream us society . government officials who oversaw indian affairs were replaced with christian clergy in order to convert indians to christianity . this policy led to violent resistance on the part of many native american tribes and was ultimately abandoned under president rutherford b. hayes. $ ^6 $ the destruction and resurrection of the reservation system in 1887 , the us congress passed the dawes act , which ended the reservation system by authorizing the federal confiscation and redistribution of tribal lands . the aim of the act was to destroy tribal governing councils and assimilate native americans into mainstream us society by replacing their communal traditions with a culture centered on the individual . to this end , tribal lands were parceled out into individual allotments , and only those indians who accepted the individual plots were allowed to become us citizens. $ ^7 $ in the 1930s , during the great depression , president franklin d. roosevelt encouraged the passage of the us indian reorganization act , which instituted a “ new deal ” for native americans , authorizing them to reorganize and form their own tribal governments . the act ended the land allotments created by dawes act and thereby resurrected the reservation system , which remains in place today. $ ^8 $ what do you think ? why was the reservation system initially implemented ? what do you see as the most significant cultural differences between native americans and european americans ? do you think life was better for native americans on the reservation or on individual plots of land ? why ?
|
the aim of the act was to destroy tribal governing councils and assimilate native americans into mainstream us society by replacing their communal traditions with a culture centered on the individual . to this end , tribal lands were parceled out into individual allotments , and only those indians who accepted the individual plots were allowed to become us citizens. $ ^7 $ in the 1930s , during the great depression , president franklin d. roosevelt encouraged the passage of the us indian reorganization act , which instituted a “ new deal ” for native americans , authorizing them to reorganize and form their own tribal governments . the act ended the land allotments created by dawes act and thereby resurrected the reservation system , which remains in place today. $ ^8 $ what do you think ?
|
when these `` tribal governments '' were created were they their own nations or no ?
|
overview the indian reservation system was created to keep native americans off of lands that european americans wished to settle . the reservation system allowed indian tribes to govern themselves and to maintain some of their cultural and social traditions . the dawes act of 1887 destroyed the reservation system by subdividing tribal lands into individual plots . from removal to the reservation from the earliest days of european colonization , bloody clashes over land and natural resources plagued relations between white settlers and native american indians . european settlers used a variety of methods to wrest land away from native inhabitants , from the negotiation of treaties to forcible removal to declarations of war. $ ^1 $ as white settlers pushed ever further westward across the american continent , these brutal conflicts over land became more frequent and more problematic for the us government . in 1824 , the office of indian affairs was created in order to resolve the land issue . the position of commissioner of indian affairs was established by an act of congress in 1832 , and in 1869 , ely samuel parker became the first native american to be appointed to the position . the office of indian affairs was renamed the bureau of indian affairs in 1947. $ ^2 $ the indian removal act of 1830 institutionalized the practice of forcing native american indians off of their ancestral lands in order to make way for european settlement . the five civilized tribes ( cherokee , chickasaw , choctaw , creek , and seminole ) were forcibly relocated to territories that would become the states of kansas , nebraska , and oklahoma , in a mass migration that became known as the trail of tears . the indian appropriations act of 1851 , also known as the appropriation bill for indian affairs , authorized the establishment of indian reservations in oklahoma and inspired the creation of reservations in other states as well . the us federal government envisioned the reservations as a useful means of keeping native american tribes off of the lands that white americans wished to settle. $ ^3 $ on the reservation many native americans resisted the imposition of the reservation system , sparking a series of conflicts known as the indian wars . through a series of bloody massacres and victories in battle , the us army ultimately succeeded in relocating most indian tribes onto the reservations . the surrounding land and natural resources of the west were thereby opened up to white settlers. $ ^4 $ for most native americans , life on the reservation was difficult . although tribes were allowed to form their own tribal councils and courts , and thus retain their traditional governing structures , indians on the reservations suffered from poverty , malnutrition , and very low standards of living and rates of economic development. $ ^5 $ in 1868 , president ulysses s. grant adopted a policy aimed at assimilating native american indians into mainstream us society . government officials who oversaw indian affairs were replaced with christian clergy in order to convert indians to christianity . this policy led to violent resistance on the part of many native american tribes and was ultimately abandoned under president rutherford b. hayes. $ ^6 $ the destruction and resurrection of the reservation system in 1887 , the us congress passed the dawes act , which ended the reservation system by authorizing the federal confiscation and redistribution of tribal lands . the aim of the act was to destroy tribal governing councils and assimilate native americans into mainstream us society by replacing their communal traditions with a culture centered on the individual . to this end , tribal lands were parceled out into individual allotments , and only those indians who accepted the individual plots were allowed to become us citizens. $ ^7 $ in the 1930s , during the great depression , president franklin d. roosevelt encouraged the passage of the us indian reorganization act , which instituted a “ new deal ” for native americans , authorizing them to reorganize and form their own tribal governments . the act ended the land allotments created by dawes act and thereby resurrected the reservation system , which remains in place today. $ ^8 $ what do you think ? why was the reservation system initially implemented ? what do you see as the most significant cultural differences between native americans and european americans ? do you think life was better for native americans on the reservation or on individual plots of land ? why ?
|
the act ended the land allotments created by dawes act and thereby resurrected the reservation system , which remains in place today. $ ^8 $ what do you think ? why was the reservation system initially implemented ? what do you see as the most significant cultural differences between native americans and european americans ?
|
why was the reservation system initially implemented ?
|
overview the indian reservation system was created to keep native americans off of lands that european americans wished to settle . the reservation system allowed indian tribes to govern themselves and to maintain some of their cultural and social traditions . the dawes act of 1887 destroyed the reservation system by subdividing tribal lands into individual plots . from removal to the reservation from the earliest days of european colonization , bloody clashes over land and natural resources plagued relations between white settlers and native american indians . european settlers used a variety of methods to wrest land away from native inhabitants , from the negotiation of treaties to forcible removal to declarations of war. $ ^1 $ as white settlers pushed ever further westward across the american continent , these brutal conflicts over land became more frequent and more problematic for the us government . in 1824 , the office of indian affairs was created in order to resolve the land issue . the position of commissioner of indian affairs was established by an act of congress in 1832 , and in 1869 , ely samuel parker became the first native american to be appointed to the position . the office of indian affairs was renamed the bureau of indian affairs in 1947. $ ^2 $ the indian removal act of 1830 institutionalized the practice of forcing native american indians off of their ancestral lands in order to make way for european settlement . the five civilized tribes ( cherokee , chickasaw , choctaw , creek , and seminole ) were forcibly relocated to territories that would become the states of kansas , nebraska , and oklahoma , in a mass migration that became known as the trail of tears . the indian appropriations act of 1851 , also known as the appropriation bill for indian affairs , authorized the establishment of indian reservations in oklahoma and inspired the creation of reservations in other states as well . the us federal government envisioned the reservations as a useful means of keeping native american tribes off of the lands that white americans wished to settle. $ ^3 $ on the reservation many native americans resisted the imposition of the reservation system , sparking a series of conflicts known as the indian wars . through a series of bloody massacres and victories in battle , the us army ultimately succeeded in relocating most indian tribes onto the reservations . the surrounding land and natural resources of the west were thereby opened up to white settlers. $ ^4 $ for most native americans , life on the reservation was difficult . although tribes were allowed to form their own tribal councils and courts , and thus retain their traditional governing structures , indians on the reservations suffered from poverty , malnutrition , and very low standards of living and rates of economic development. $ ^5 $ in 1868 , president ulysses s. grant adopted a policy aimed at assimilating native american indians into mainstream us society . government officials who oversaw indian affairs were replaced with christian clergy in order to convert indians to christianity . this policy led to violent resistance on the part of many native american tribes and was ultimately abandoned under president rutherford b. hayes. $ ^6 $ the destruction and resurrection of the reservation system in 1887 , the us congress passed the dawes act , which ended the reservation system by authorizing the federal confiscation and redistribution of tribal lands . the aim of the act was to destroy tribal governing councils and assimilate native americans into mainstream us society by replacing their communal traditions with a culture centered on the individual . to this end , tribal lands were parceled out into individual allotments , and only those indians who accepted the individual plots were allowed to become us citizens. $ ^7 $ in the 1930s , during the great depression , president franklin d. roosevelt encouraged the passage of the us indian reorganization act , which instituted a “ new deal ” for native americans , authorizing them to reorganize and form their own tribal governments . the act ended the land allotments created by dawes act and thereby resurrected the reservation system , which remains in place today. $ ^8 $ what do you think ? why was the reservation system initially implemented ? what do you see as the most significant cultural differences between native americans and european americans ? do you think life was better for native americans on the reservation or on individual plots of land ? why ?
|
why was the reservation system initially implemented ? what do you see as the most significant cultural differences between native americans and european americans ? do you think life was better for native americans on the reservation or on individual plots of land ?
|
what do you see as the most significant cultural differences between native americans and european americans ?
|
a procession for a royal visit on december 17 , 1953 , a newly crowned queen elizabeth ii and her husband prince philip , duke of edinburgh , arrived on the island of fiji , then an english colony , and stayed for three days before continuing on their first tour of the commonwealth nations of england in the pacific islands . while the precise date of the photograph depicted above is unknown , there is still much that can be learned both about fijian art and culture and the queen ’ s historic visit . the first thing you might notice in the photograph is the procession of fijian women making their way through a group of seated fijian men and women . barkcloth several of the processing women are wearing skirts made of barkcloth painted with geometric patterns . barkcloth , or masi , as it is referred to in fiji , is made by stripping the inner bark of mulberry trees , soaking the bark , then beating it into strips of cloth that are glued together , often by a paste made of arrowroot . bold and intricate geometric patterns in red , white , and black are often painted onto the masi . the practice of making masi continues in fiji , where the cloth is often presented as gifts in important ceremonies such as weddings and funerals , or to commemorate significant events , such as a visit by the queen of england . while in this photograph , the masi is only worn by the women and not carried , as far as can be ascertained in this picture ; it is very likely that the women also presented the cloth to the queen to celebrate the occasion of her visit . mats what is definitely evident from the photograph are the rolls of woven mats that each woman in the procession carries . like masi , fijian mats served and continue to serve an important purpose in fijian society as a type of ritual exchange and tribute . made by women , fijian mats are begun by stripping , boiling , drying , blackening , and then softening leaves from the pandanus plant . the dried leaves are then woven into tight , often diagonal patterns that culminate in frayed or fringed edges . while the mats that the women in this photograph are carrying may seem too plain to present to the queen of england , their simplicity is an indication of their importance . in fiji , the more simple the design , the more meaningful its function . fijian artists continue to create mats and it is a practice that is growing , with many mats beings sold at market , often to tourists . with the advent of processed pandanus , they are more widely available than masi , and used heavily in wedding and funeral rituals . in addition to masi and mats , fijian art also includes elaborately carvings made of wood or ivory , as well as small woven god houses called bure kalou ( left ) , which provided a pathway for the god to descend to the priest . the queen 's itinerary returning to the queen ’ s visit in 1953 , while in fiji she visited hospitals and schools and held meetings with various fijian politicians . she witnessed elaborate performances of traditional fijian dances and songs and even participated in a kava ceremony , which was ( and continues to be ) an important aspect of fijian culture . the kava drink is a kind of tea made from the kava root and is sipped by members of the community , in order of importance . on the occasion of the queen ’ s visit , she was , as you might imagine , given the first sip of kava . in thinking about the importance of the kava ceremony , consider what might happen if everyone from a large group takes a sip from the same cup and of the same liquid . although sipped in order of hierarchical importance , it would , in the end , put everyone in the group on the same level before beginning the event , meeting , or ceremony . after three days on the island of fiji , queen elizabeth ii and prince philip departed for the kingdom of tonga where they stayed for two days before leaving for extended stays in new zealand and australia . on tonga , they were greeted warmly by queen sälote and other members of the royal tongan family . on the occasion of her visit to tonga , an enormous barkcloth was commissioned in queen elizabeth ’ s honor and had her initials , “ eriii , ” painted onto the rare piece of ngatu . referred to as ngatu launima in tongan , it is just shy of 75 feet in length and is significant not only because it commemorated queen elizabeth ’ s visit , but also because it was placed under the coffin of queen sälote when her body was flown back to tonga in 1960 after an extended stay in a new zealand hospital . the barkcloth is now in the collection of te papa tongarewa/museum of new zealand , after being donated by the pilot who had flown queen sälote ’ s body back to tonga , to whom the barkcloth had been given by the tongan royal family . essay by dr. jennifer wagelie additional resources : this photograph in the national library of new zealand short film on queen elizabeth ii ’ s visit to fiji , december 1953 short film on queen elizabeth ii ’ s visit to tonga , december 1953 photographs of queen elizabeth ii ’ s visit to fiji , december 1953 information on the barkcloth commissioned in queen elizabeth ii ’ s honor more information on barkcloth or tapa rod ewins , mat-weaving in gau , fiji ( fiji museum special publication , 1982 ) . -- -- -- -- -- staying fijian : vatulele island barkcloth and social identity ( adelaide : crawford house publishing , 2006 ) . -- -- -- -- -- traditional fijian artifacts ( nubeena , tasmania : just pacific , 2014 ) . j.w . sykes , the royal visit to the colony of fiji of her majesty queen elizabeth ii and his royal highness the duke of edinburgh ( december 1953 ) .
|
mats what is definitely evident from the photograph are the rolls of woven mats that each woman in the procession carries . like masi , fijian mats served and continue to serve an important purpose in fijian society as a type of ritual exchange and tribute . made by women , fijian mats are begun by stripping , boiling , drying , blackening , and then softening leaves from the pandanus plant .
|
how would people know what type of art to do ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures .
|
40 calories more to heat up 1c as it takes in the boiling point ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water .
|
how come there is such a tiny difference , or is it actually a huge difference ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes .
|
but why is the distance between molecules in ice bigger than in water ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ?
|
in the last paragraph it says : `` in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier ... '' how does ice provide an insulating barrier ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid .
|
why do the fastest-moving molecules leave the liquid ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures .
|
what happens when you apply heat to a glass of water ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water .
|
how to estimate density of following substances in increasing order ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system .
|
is there really calories like on candy bars in water ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology .
|
to make sure i understand this correctly , usually when molecules go from liquid to solid they come together , but in the case of water the molecules become more spatial ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) .
|
if hydrogen bonds are regarded as `` weak '' polar covalent bonds , as stated in the definition in an early lesson , why does it take so much ke to break ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) .
|
why are hydrogen bonds called `` weak '' bonds ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system .
|
i 'm just curious about the situation when the water molecules are in a vaccum ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures .
|
specific heat of vaporization of water ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand .
|
how does the shape of a water molecule affect its high specific heat ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures .
|
if i put a potato in a pot of boiling water ( water that has reached 100c or close enough ( what actually makes the potato cook , become soft and edible ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night .
|
what is the explanation for why water cools down slower than sand with regards to specific heat capacity ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes .
|
in the paragraph of density of ice and water , why are the water molecules pushed farther apart and in other liquids the molecules are not ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand .
|
what does high capacity mean ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand .
|
what is the difference between heat and temperature ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point .
|
why do we consider calories to be the amount of energy stored in food ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid .
|
what about molecules at absolute zero temperature , do they really stay in stationary state ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water .
|
could you please explain more specially ice has a more density than water ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius .
|
should n't the stronger bonds ( like metallic or ionic ) have a higher heat capacity than water ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures .
|
if i have a beaker of water and heat it for 5 mins , if i want to find net q transferred to the water , and 1g of water is lost in evaporation , does the formula become q=cm ( tf-ti ) +lv ( 1 ) ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water .
|
i.e has energy been used to vaporise some water , but not raise the temperature ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes .
|
why the water molecule in ice ca n't be closer than in water ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes .
|
is it because in the ice state , the water molecule has less energy to resist the repel energy between the molecules and the repel energy is not big enough to break the hydrogen , so they can only connect with each other with certain distance ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night .
|
why is specific heat capacity important within the food industry ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures .
|
how does specific heat affect the vaporization speed of water ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas .
|
does evapotranspiration in plants works similarly ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water .
|
why do hydrogen bonds release energy when they form ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night .
|
can specific heat be negative in any situation ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie .
|
what does the evaporating cooling of a human have in common with the one with a lake or a river ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) .
|
so , the hydrogen bonds keep the molecules at a fix distant ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water .
|
if water freezing results in a less dense solid due to the fact that it has a hydrogen bond , then does methane do the same thing ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system .
|
why do hydrogen bonds have to be broken in order to increase water molecules ' speed ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water .
|
what about the ice in the north and south arctic caps area ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing .
|
what cause for some of the type of icebergs to become small on the surface but dense colossus of been tough as metal at the bottom of the ocean ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night .
|
what determines the specific heat capacity of different substances ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system .
|
is water made of 2 oxygen atoms and 1 hydrogen atom ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water .
|
what is the density of water and ice ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ?
|
how do you think the properties of the ballon have changed ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand .
|
how does high heat of vaporization life on earth ?
|
introduction let ’ s imagine that it ’ s a hot day . you ’ ve just been out in the sun for awhile , and you ’ re sweating quite a bit as you sit down and grab a glass of cool ice water . you idly notice both the sweat beads on your arms and the chunks of ice floating at the top of your water glass . thanks to your hard work studying the properties of water , you recognize both the sweat on your arms and the floating ice cubes in your glass as examples of water 's amazing capacity for hydrogen bonding . how does that work ? water molecules are very good at forming hydrogen bonds , weak associations between the partially positive and partially negative ends of the molecules . hydrogen bonding explains both the effectiveness of evaporative cooling ( why sweating cools you off ) and the low density of ice ( why ice floats ) . here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology . in liquid water , hydrogen bonds are constantly being formed and broken as the water molecules slide past each other . the breaking of these bonds is caused by the energy of motion ( kinetic energy ) of the water molecules due to the heat contained in the system . when the heat is raised ( for instance , as water is boiled ) , the higher kinetic energy of the water molecules causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas . we observe this gas as water vapor or steam . on the other hand , when the temperature drops and water freezes , water molecules form a crystal structure maintained by hydrogen bonding ( as there is too little heat energy left to break the hydrogen bonds ) . this structure makes ice less dense than liquid water . density of ice and water water ’ s lower density in its solid form is due to the way hydrogen bonds are oriented as it freezes . specifically , in ice , the water molecules are pushed farther apart than they are in liquid water . that means water expands when it freezes . you may have seen this for yourself if you 've ever put a sealed glass container containing a mostly-watery food ( soup , soda , etc . ) into the freezer , only to have it crack or explode as the liquid water inside froze and expanded . with most other liquids , solidification—which occurs when the temperature drops and kinetic ( motion ) energy of molecules is reduced—allows molecules to pack more tightly than in liquid form , giving the solid a greater density than the liquid . water is an anomaly ( that is , a weird standout ) in its lower density as a solid . because it is less dense , ice floats on the surface of liquid water , as we see for an iceberg or the ice cubes in a glass of iced tea . in lakes and ponds , a layer of ice forms on top of the liquid water , creating an insulating barrier that protects the animals and plant life in the pond below from freezing . why is it harmful for living things to freeze ? we can understand this by thinking back to the case of a bottle of soda pop cracking in the freezer . when a cell freezes , its watery contents expand and its membrane ( just like the soda bottle ) is broken into pieces . heat capacity of water it takes a lot of heat to increase the temperature of liquid water because some of the heat must be used to break hydrogen bonds between the molecules . in other words , water has a high specific heat capacity , which is defined as the amount of heat needed to raise the temperature of one gram of a substance by one degree celsius . the amount of heat needed to raise the temperature of 1 g water by 1 °c is has its own name , the calorie . because of its high heat capacity , water can minimize changes in temperature . for instance , the specific heat capacity of water is about five times greater than that of sand . the land cools faster than the sea once the sun goes down , and the slow-cooling water can release heat to nearby land during the night . water is also used by warm-blooded animals to distribute heat through their bodies : it acts similarly to a car ’ s cooling system , moving heat from warm places to cool places , helping the body keep an even temperature . heat of vaporization of water just as it takes a lot of heat to increase the temperature of liquid water , it also takes an unusual amount of heat to vaporize a given amount of water , because hydrogen bonds must be broken in order for the molecules to fly off as gas . that is , water has a high heat of vaporization , the amount of energy needed to change one gram of a liquid substance to a gas at constant temperature . water ’ s heat of vaporization is around 540 cal/g at 100 °c , water 's boiling point . note that some molecules of water – ones that happen to have high kinetic energy – will escape from the surface of the water even at lower temperatures . as water molecules evaporate , the surface they evaporate from gets cooler , a process called evaporative cooling . this is because the molecules with the highest kinetic energy are lost to evaporation ( see the video on evaporative cooling for more info ) . in humans and other organisms , the evaporation of sweat , which is 90 % water , cools the body to maintain a steady temperature .
|
here , we ’ ll take a closer look at the role of hydrogen bonding in temperature changes , freezing , and vaporization of water . water : solid , liquid , and gas water has unique chemical characteristics in all three states—solid , liquid , and gas—thanks to the ability of its molecules to hydrogen bond with one another . since living things , from human beings to bacteria , have a high water content , understanding the unique chemical features of water in its three states is key to biology .
|
boiling need tempreture to liquid turn to gas , why evaporation do n't need tempreture ?
|
the sat essay—part one focus : becoming familiar with the sat® essay student objective understand the scope and purpose of the task of the sat essay . before the lesson ☐ review chapter 14 of the sat study guide for students . ☐ preview the sat essay overview video . ☐ preview and print ( if necessary ) the student materials . introductory activity ( 20 minutes ) be sure to let students know some basic facts about the sat essay : a. it ’ s optional , though students should research whether the schools they are considering require the essay , recommend it , or neither . a regularly updated list for students to consult can be found here . b . students have 50 minutes to read the passage and to write a response . c. the prompt won ’ t ask you to take a stance on an issue . rather , your task will be to analyze an argument presented in a passage in order to explain how the author builds the argument to persuade his or her audience . d. it ’ s scored on the following aspects : reading : how well you demonstrated your understanding of the passage . analysis : how well you analyzed the passage and carried out the task of explaining how the author of builds his or her argument to persuade an audience . writing : how skillfully you crafted your response . e. you may want to show students this introductory video . the most important aspect to emphasize to students is that the purpose of their essay is to identify and analyze the tactics that the author uses to build the argument . ask students to brainstorm a list of ways that , in general , writers ( or speakers ) try to convince their readers ( or audiences ) . they should say things like : facts , evidence , logical reasoning , but you should try to get them to think about how language , specifically diction and syntax , can also be used . let students know that the prompt for the sat essay always remains the same ; it ’ s only the text that they analyze that changes . the prompt , included in the student materials for this lesson , will ask students to consider the following elements : a . evidence , such as facts or examples , to support claims . b . reasoning to develop ideas and to connect claims and evidence . c. stylistic or persuasive elements , such as word choice or appeals to emotion , to add power to the ideas expressed . look at the opening paragraphs of a sample text and ask students to identify any of the above elements that the writer uses to persuade his audience that news organizations should increase the amount of professional foreign news coverage provided to people in the united states . ask students to think about how these first three paragraphs strengthen the logic and persuasiveness of goodwin ’ s argument . remind students that they are not to focus on whether they agree or disagree with the author , or to summarize what the author is saying , but to focus on the tactics he uses . let students know that the prompt for the sat essay always remains the same ; it ’ s only the text that they analyze that changes . the prompt , included in the student materials for this lesson , will ask students to consider the following elements : a . evidence , such as facts or examples , to support claims . b . reasoning to develop ideas and to connect claims and evidence . c. stylistic or persuasive elements , such as word choice or appeals to emotion , to add power to the ideas expressed . look at the opening paragraphs of a sample text and ask students to identify any of the above elements that the writer uses to persuade his audience that news organizations should increase the amount of professional foreign news coverage provided to people in the united states . ask students to think about how these first three paragraphs strengthen the logic and persuasiveness of goodwin ’ s argument . remind students that they are not to focus on whether they agree or disagree with the author , or to summarize what the author is saying , but to focus on the tactics he uses . group/pair practice ( 20 minutes ) in pairs or small groups , ask students to read the remaining article aloud , marking places where the author uses evidence , reasoning , and/or stylistic elements . students should discuss the following question : what does the author include to try to persuade his audience about the need for foreign journalism ? ask them to fill in a chart of examples of the following elements : evidence | logical reasoning | stylistic elements -| | | $ $ || independent practice ( 10 minutes ) ask students to read a student ’ s sample response to the sat essay prompt about the text that they just read . let them know that this one met the expectations of the essay ( received 3s on all traits out of 4 ) . students should summarize the main points that the student writer makes about the persuasiveness of the text . what were the elements the student focused on ? what are the portions of the essay that are similar to other essays students have written ? how is it different ? ask students to imagine that they were going to explain to someone how to take the sat essay . what would they say ? what is its goal ? homework ( 30 minutes ) read at least three more student sample responses , starting on page 185 . students should also read the articles in the sat essay strategies section of the tips and strategies tab on official sat practice . student materials—lesson 9 introductory activity the sat prompt as you read the passage below , consider how peter s. goodman uses evidence , such as facts or examples , to support claims . reasoning to develop ideas and to connect claims and evidence . stylistic or persuasive elements , such as word choice or appeals to emotion , to add power to the ideas expressed . write an essay in which you explain how peter s. goodman builds an argument to persuade his audience that news organizations should increase the amount of professional foreign news coverage provided to people in the united states . in your essay , analyze how goodman uses one or more of the features listed in the box above ( or features of your own choice ) to strengthen the logic and persuasiveness of his argument . be sure that your analysis focuses on the most relevant features of the passage . your essay should not explain whether you agree with goodman 's claims , but rather explain how the author builds argument to persuade goodman 's audience . adapted from peter s. goodman , “ foreign news at a crisis point. ” ©2013 by thehuffingtonpost.com , inc . originally published september 25 , 2013 . peter goodman is the executive business and global news editor at thehuffingtonpost.com . pair/group activity as you read the rest of the article , identify the following : evidence | logical reasoning | stylistic elements -| | | $ $ || independent practice read the following student essay in response to the article that you examined . as you read , keep track of how the student writer addresses the prompt and creates an effective essay . student sample # 1
|
before the lesson ☐ review chapter 14 of the sat study guide for students . ☐ preview the sat essay overview video . ☐ preview and print ( if necessary ) the student materials .
|
how long should the essay usually be ?
|
in all world cultures , artists honor remarkable leaders by creating lasting works of art in their honor . historical leaders in the west , like charlemagne and alexander the great were celebrated for their accomplishments during their lifetime and remembered through many works of art created to preserve their legacy . during the first half of the eighteenth century , the kuba king mishe mishyaang mambul was celebrated throughout his kingdom for his generosity and for the great number of his loyal subjects . he was even the recipient of his own praise song . at the height of his reign in 1710 , he commissioned an idealized portrait-statue called an ndop . with the commission of his ndop , mishe mishyaang mambul recorded his reign for posterity and solidified his accomplishments amongst the pantheon of his predecessors . the ndop that portrayed his likeness was eventually purchased by the brooklyn museum in 1961 and has been on view at the museum since that time . it was first collected in 1909 by a colonial minister in what was then the belgian congo , the european country ’ s colony . why are mishe mishyaang mambul and others commemorated in the arts of africa largely unknown to us ? unlike in euro-american contexts , history in sub-saharan africa was not written down by members of cultural communities until colonialism in the late nineteenth and early twentieth centuries . instead of written records , oral narrative was the primary method for collective and personal histories to be passed down from one generation to the next . as these spoken histories were passed down , they were changed and adapted to reflect their times . the changing nature of oral narrative is like a highly complex game of telephone , where the words can be changed and often only the spirit of the original meaning is preserved . before being purchased by western collectors and museums , african sculptures served as important historical markers within their communities . the ndop sculptural record helps freeze a moment in time that would otherwise be transformed during its transmission from generation to generation . when we look at these sculptures in museums , it is important to remember that they were created about , and for , individuals . since information and history was transferred orally in africa , sculptural traditions like the ndop can help us gain insight into information about historical individuals and their cultural ideals . the kuba artist the kuba live in the democratic republic of the congo on the southern fringes of the equatorial forest in an area bounded by two rivers called the kasai and sankuru . over a period of three centuries of movement and exchange beginning in the 17th century , this loose confederacy of people formed into a durable kingdom . since that time , the name “ kuba ” largely refers to nineteen unique but related ethnic groups , all of which acknowledge the leadership of the same leader ( nyim ) . the kuba are renowned for a dynamic artistic legacy across media . historically , kuba artists were professional woodcarvers , blacksmiths , and weavers who worked exclusively for the nyim . kuba artists learned their art by becoming apprentices to others who were well-known and accomplished in their community . similar to art traditions in other world cultures , the apprentices imitated or copied early pieces from their teachers until they were skilled enough to develop their own designs . although the names of individual artists were not written down—and are not known to us today—artists were sought after by name and were important to the kuba royal court and beyond . ndop sculpture the ndop statues might be the the most revered of all kuba art forms . the ndop ( literally meaning “ statue ” ) are a genre of figurative wood sculpture that portrays important kuba leaders throughout the eighteenth to twentieth centuries . art historians believe that there are seven ndop statues of historical significance in western museums . these seven are significant because the lives of the nyim they portray were celebrated in oral histories that were recorded and written down by early european visitors , so we know the most about them . you can travel to the british museum in england or the royal museum for central africa in belgium to see ndop . ndop sculptures that are on view at the british museum were brought to europe from africa by hungarian ethnographer emil torday . torday and other early visitors to the kuba court documented oral traditions related to artwork . art historians have since tried to reconstruct and sort out these early accounts ; they use the sculptures themselves to interpret precolonial kuba history . ndop sculpture have rounded contours creating forms that define the head , shoulders and stomach , and also feature a defined collarbone . while the relative naturalism may appear to have been informed by an artist ’ s one-to-one observation of the nyim , ndop sculptures aren ’ t exact likenesses ; they are not actually created from direct observation . instead , cultural conventions and visual precedents guide the artists in making the sculpture . the expression on the face , the position of the body , and the regalia were meant to faithfully represent the ideal of a king—but not an individual king . for example , the facial features of each statue follow sculpting conventions and do not represent features of a specific individual . all figures are sculpted using a one-to-three proportion—the head of the statue was sculpted to be one third the size of the total statue . kuba artists emphasized the head because it was considered to be the seat of intelligence , a valued ideal . how are we able to identify each ndop , then ? there are specific attributes that link each ndop to named individuals . all ndop sculpture would feature a geometric motif and an emblem ( ibol ) , chosen by the nyim when he was installed as a leader and commissioned his ndop . the geometric motif pattern and the ibol served as identifying symbols of his reign and was sculpted in prominent relief on the front of each base . the ibol is a signifier that gives the ndop its particular identity , making it clear who the sculpture portrays and what reign it represents . a drum with a severed hand is the ibol for mishe mishyaang mambul ’ s reign , and that helps us identify the sculpture as his likeness . other styles or conventions that were followed by sculptors of ndop can be found in royal regalia such as belts , armbands , bracelets , shoulder ornaments , and a unique projecting headdress , called a shody . the arms of each ndop extend vertically at either side of the torso , with the left hand grasping the handle of a ceremonial knife ( ikul ) and the right hand resting on the knee . artists decorated the surface of the sculpture by carving representations of what was conventionally worn ; the finely chiseled details correspond to objects that represent the prerogative and prestige of the nyim . the ndop of mishe mishyaang mambul is part of a larger genre of figurative wood sculpture in kuba art . these sculptures were commissioned by kuba leaders or nyim to preserve their accomplishments for posterity . because transmission of knowledge in this part of africa is through oral narrative , names and histories of the past are often lost . the ndop sculptures serve as important markers of cultural ideals . they also reveal a chronological lineage through their visual signifiers . text by roger d. arnold additional reading binkley , david a. and patricia darish . kuba . milan : 5 continents press , 2010 . lagamma , alisa . heroic africans : legendary leaders , iconic sculptures . new york : metropolitan museum of art , 2011 . siegmann , william and joseph adande . african art : a century at the brooklyn museum . new york : prestel , 2009 . vansina , jan. “ recording the oral history of the bakuba. ” journal of african history 1:1 , 1960 , 43 – 61 .
|
why are mishe mishyaang mambul and others commemorated in the arts of africa largely unknown to us ? unlike in euro-american contexts , history in sub-saharan africa was not written down by members of cultural communities until colonialism in the late nineteenth and early twentieth centuries . instead of written records , oral narrative was the primary method for collective and personal histories to be passed down from one generation to the next .
|
in paragraph 2 , it mentions that sub saharan african communities did not keep written records , and while orthographic scripts were rare on the continent , would ge'ez not be a sub saharan script , and an ancient one at that ?
|
in all world cultures , artists honor remarkable leaders by creating lasting works of art in their honor . historical leaders in the west , like charlemagne and alexander the great were celebrated for their accomplishments during their lifetime and remembered through many works of art created to preserve their legacy . during the first half of the eighteenth century , the kuba king mishe mishyaang mambul was celebrated throughout his kingdom for his generosity and for the great number of his loyal subjects . he was even the recipient of his own praise song . at the height of his reign in 1710 , he commissioned an idealized portrait-statue called an ndop . with the commission of his ndop , mishe mishyaang mambul recorded his reign for posterity and solidified his accomplishments amongst the pantheon of his predecessors . the ndop that portrayed his likeness was eventually purchased by the brooklyn museum in 1961 and has been on view at the museum since that time . it was first collected in 1909 by a colonial minister in what was then the belgian congo , the european country ’ s colony . why are mishe mishyaang mambul and others commemorated in the arts of africa largely unknown to us ? unlike in euro-american contexts , history in sub-saharan africa was not written down by members of cultural communities until colonialism in the late nineteenth and early twentieth centuries . instead of written records , oral narrative was the primary method for collective and personal histories to be passed down from one generation to the next . as these spoken histories were passed down , they were changed and adapted to reflect their times . the changing nature of oral narrative is like a highly complex game of telephone , where the words can be changed and often only the spirit of the original meaning is preserved . before being purchased by western collectors and museums , african sculptures served as important historical markers within their communities . the ndop sculptural record helps freeze a moment in time that would otherwise be transformed during its transmission from generation to generation . when we look at these sculptures in museums , it is important to remember that they were created about , and for , individuals . since information and history was transferred orally in africa , sculptural traditions like the ndop can help us gain insight into information about historical individuals and their cultural ideals . the kuba artist the kuba live in the democratic republic of the congo on the southern fringes of the equatorial forest in an area bounded by two rivers called the kasai and sankuru . over a period of three centuries of movement and exchange beginning in the 17th century , this loose confederacy of people formed into a durable kingdom . since that time , the name “ kuba ” largely refers to nineteen unique but related ethnic groups , all of which acknowledge the leadership of the same leader ( nyim ) . the kuba are renowned for a dynamic artistic legacy across media . historically , kuba artists were professional woodcarvers , blacksmiths , and weavers who worked exclusively for the nyim . kuba artists learned their art by becoming apprentices to others who were well-known and accomplished in their community . similar to art traditions in other world cultures , the apprentices imitated or copied early pieces from their teachers until they were skilled enough to develop their own designs . although the names of individual artists were not written down—and are not known to us today—artists were sought after by name and were important to the kuba royal court and beyond . ndop sculpture the ndop statues might be the the most revered of all kuba art forms . the ndop ( literally meaning “ statue ” ) are a genre of figurative wood sculpture that portrays important kuba leaders throughout the eighteenth to twentieth centuries . art historians believe that there are seven ndop statues of historical significance in western museums . these seven are significant because the lives of the nyim they portray were celebrated in oral histories that were recorded and written down by early european visitors , so we know the most about them . you can travel to the british museum in england or the royal museum for central africa in belgium to see ndop . ndop sculptures that are on view at the british museum were brought to europe from africa by hungarian ethnographer emil torday . torday and other early visitors to the kuba court documented oral traditions related to artwork . art historians have since tried to reconstruct and sort out these early accounts ; they use the sculptures themselves to interpret precolonial kuba history . ndop sculpture have rounded contours creating forms that define the head , shoulders and stomach , and also feature a defined collarbone . while the relative naturalism may appear to have been informed by an artist ’ s one-to-one observation of the nyim , ndop sculptures aren ’ t exact likenesses ; they are not actually created from direct observation . instead , cultural conventions and visual precedents guide the artists in making the sculpture . the expression on the face , the position of the body , and the regalia were meant to faithfully represent the ideal of a king—but not an individual king . for example , the facial features of each statue follow sculpting conventions and do not represent features of a specific individual . all figures are sculpted using a one-to-three proportion—the head of the statue was sculpted to be one third the size of the total statue . kuba artists emphasized the head because it was considered to be the seat of intelligence , a valued ideal . how are we able to identify each ndop , then ? there are specific attributes that link each ndop to named individuals . all ndop sculpture would feature a geometric motif and an emblem ( ibol ) , chosen by the nyim when he was installed as a leader and commissioned his ndop . the geometric motif pattern and the ibol served as identifying symbols of his reign and was sculpted in prominent relief on the front of each base . the ibol is a signifier that gives the ndop its particular identity , making it clear who the sculpture portrays and what reign it represents . a drum with a severed hand is the ibol for mishe mishyaang mambul ’ s reign , and that helps us identify the sculpture as his likeness . other styles or conventions that were followed by sculptors of ndop can be found in royal regalia such as belts , armbands , bracelets , shoulder ornaments , and a unique projecting headdress , called a shody . the arms of each ndop extend vertically at either side of the torso , with the left hand grasping the handle of a ceremonial knife ( ikul ) and the right hand resting on the knee . artists decorated the surface of the sculpture by carving representations of what was conventionally worn ; the finely chiseled details correspond to objects that represent the prerogative and prestige of the nyim . the ndop of mishe mishyaang mambul is part of a larger genre of figurative wood sculpture in kuba art . these sculptures were commissioned by kuba leaders or nyim to preserve their accomplishments for posterity . because transmission of knowledge in this part of africa is through oral narrative , names and histories of the past are often lost . the ndop sculptures serve as important markers of cultural ideals . they also reveal a chronological lineage through their visual signifiers . text by roger d. arnold additional reading binkley , david a. and patricia darish . kuba . milan : 5 continents press , 2010 . lagamma , alisa . heroic africans : legendary leaders , iconic sculptures . new york : metropolitan museum of art , 2011 . siegmann , william and joseph adande . african art : a century at the brooklyn museum . new york : prestel , 2009 . vansina , jan. “ recording the oral history of the bakuba. ” journal of african history 1:1 , 1960 , 43 – 61 .
|
the ibol is a signifier that gives the ndop its particular identity , making it clear who the sculpture portrays and what reign it represents . a drum with a severed hand is the ibol for mishe mishyaang mambul ’ s reign , and that helps us identify the sculpture as his likeness . other styles or conventions that were followed by sculptors of ndop can be found in royal regalia such as belts , armbands , bracelets , shoulder ornaments , and a unique projecting headdress , called a shody .
|
why was king mishe mishyaang mambul 's ibol a severed hand with a drum ?
|
in all world cultures , artists honor remarkable leaders by creating lasting works of art in their honor . historical leaders in the west , like charlemagne and alexander the great were celebrated for their accomplishments during their lifetime and remembered through many works of art created to preserve their legacy . during the first half of the eighteenth century , the kuba king mishe mishyaang mambul was celebrated throughout his kingdom for his generosity and for the great number of his loyal subjects . he was even the recipient of his own praise song . at the height of his reign in 1710 , he commissioned an idealized portrait-statue called an ndop . with the commission of his ndop , mishe mishyaang mambul recorded his reign for posterity and solidified his accomplishments amongst the pantheon of his predecessors . the ndop that portrayed his likeness was eventually purchased by the brooklyn museum in 1961 and has been on view at the museum since that time . it was first collected in 1909 by a colonial minister in what was then the belgian congo , the european country ’ s colony . why are mishe mishyaang mambul and others commemorated in the arts of africa largely unknown to us ? unlike in euro-american contexts , history in sub-saharan africa was not written down by members of cultural communities until colonialism in the late nineteenth and early twentieth centuries . instead of written records , oral narrative was the primary method for collective and personal histories to be passed down from one generation to the next . as these spoken histories were passed down , they were changed and adapted to reflect their times . the changing nature of oral narrative is like a highly complex game of telephone , where the words can be changed and often only the spirit of the original meaning is preserved . before being purchased by western collectors and museums , african sculptures served as important historical markers within their communities . the ndop sculptural record helps freeze a moment in time that would otherwise be transformed during its transmission from generation to generation . when we look at these sculptures in museums , it is important to remember that they were created about , and for , individuals . since information and history was transferred orally in africa , sculptural traditions like the ndop can help us gain insight into information about historical individuals and their cultural ideals . the kuba artist the kuba live in the democratic republic of the congo on the southern fringes of the equatorial forest in an area bounded by two rivers called the kasai and sankuru . over a period of three centuries of movement and exchange beginning in the 17th century , this loose confederacy of people formed into a durable kingdom . since that time , the name “ kuba ” largely refers to nineteen unique but related ethnic groups , all of which acknowledge the leadership of the same leader ( nyim ) . the kuba are renowned for a dynamic artistic legacy across media . historically , kuba artists were professional woodcarvers , blacksmiths , and weavers who worked exclusively for the nyim . kuba artists learned their art by becoming apprentices to others who were well-known and accomplished in their community . similar to art traditions in other world cultures , the apprentices imitated or copied early pieces from their teachers until they were skilled enough to develop their own designs . although the names of individual artists were not written down—and are not known to us today—artists were sought after by name and were important to the kuba royal court and beyond . ndop sculpture the ndop statues might be the the most revered of all kuba art forms . the ndop ( literally meaning “ statue ” ) are a genre of figurative wood sculpture that portrays important kuba leaders throughout the eighteenth to twentieth centuries . art historians believe that there are seven ndop statues of historical significance in western museums . these seven are significant because the lives of the nyim they portray were celebrated in oral histories that were recorded and written down by early european visitors , so we know the most about them . you can travel to the british museum in england or the royal museum for central africa in belgium to see ndop . ndop sculptures that are on view at the british museum were brought to europe from africa by hungarian ethnographer emil torday . torday and other early visitors to the kuba court documented oral traditions related to artwork . art historians have since tried to reconstruct and sort out these early accounts ; they use the sculptures themselves to interpret precolonial kuba history . ndop sculpture have rounded contours creating forms that define the head , shoulders and stomach , and also feature a defined collarbone . while the relative naturalism may appear to have been informed by an artist ’ s one-to-one observation of the nyim , ndop sculptures aren ’ t exact likenesses ; they are not actually created from direct observation . instead , cultural conventions and visual precedents guide the artists in making the sculpture . the expression on the face , the position of the body , and the regalia were meant to faithfully represent the ideal of a king—but not an individual king . for example , the facial features of each statue follow sculpting conventions and do not represent features of a specific individual . all figures are sculpted using a one-to-three proportion—the head of the statue was sculpted to be one third the size of the total statue . kuba artists emphasized the head because it was considered to be the seat of intelligence , a valued ideal . how are we able to identify each ndop , then ? there are specific attributes that link each ndop to named individuals . all ndop sculpture would feature a geometric motif and an emblem ( ibol ) , chosen by the nyim when he was installed as a leader and commissioned his ndop . the geometric motif pattern and the ibol served as identifying symbols of his reign and was sculpted in prominent relief on the front of each base . the ibol is a signifier that gives the ndop its particular identity , making it clear who the sculpture portrays and what reign it represents . a drum with a severed hand is the ibol for mishe mishyaang mambul ’ s reign , and that helps us identify the sculpture as his likeness . other styles or conventions that were followed by sculptors of ndop can be found in royal regalia such as belts , armbands , bracelets , shoulder ornaments , and a unique projecting headdress , called a shody . the arms of each ndop extend vertically at either side of the torso , with the left hand grasping the handle of a ceremonial knife ( ikul ) and the right hand resting on the knee . artists decorated the surface of the sculpture by carving representations of what was conventionally worn ; the finely chiseled details correspond to objects that represent the prerogative and prestige of the nyim . the ndop of mishe mishyaang mambul is part of a larger genre of figurative wood sculpture in kuba art . these sculptures were commissioned by kuba leaders or nyim to preserve their accomplishments for posterity . because transmission of knowledge in this part of africa is through oral narrative , names and histories of the past are often lost . the ndop sculptures serve as important markers of cultural ideals . they also reveal a chronological lineage through their visual signifiers . text by roger d. arnold additional reading binkley , david a. and patricia darish . kuba . milan : 5 continents press , 2010 . lagamma , alisa . heroic africans : legendary leaders , iconic sculptures . new york : metropolitan museum of art , 2011 . siegmann , william and joseph adande . african art : a century at the brooklyn museum . new york : prestel , 2009 . vansina , jan. “ recording the oral history of the bakuba. ” journal of african history 1:1 , 1960 , 43 – 61 .
|
he was even the recipient of his own praise song . at the height of his reign in 1710 , he commissioned an idealized portrait-statue called an ndop . with the commission of his ndop , mishe mishyaang mambul recorded his reign for posterity and solidified his accomplishments amongst the pantheon of his predecessors .
|
if the statue was commissioned in 1710 , then why does the identification i received and the picture identification say 1760-80 ?
|
in all world cultures , artists honor remarkable leaders by creating lasting works of art in their honor . historical leaders in the west , like charlemagne and alexander the great were celebrated for their accomplishments during their lifetime and remembered through many works of art created to preserve their legacy . during the first half of the eighteenth century , the kuba king mishe mishyaang mambul was celebrated throughout his kingdom for his generosity and for the great number of his loyal subjects . he was even the recipient of his own praise song . at the height of his reign in 1710 , he commissioned an idealized portrait-statue called an ndop . with the commission of his ndop , mishe mishyaang mambul recorded his reign for posterity and solidified his accomplishments amongst the pantheon of his predecessors . the ndop that portrayed his likeness was eventually purchased by the brooklyn museum in 1961 and has been on view at the museum since that time . it was first collected in 1909 by a colonial minister in what was then the belgian congo , the european country ’ s colony . why are mishe mishyaang mambul and others commemorated in the arts of africa largely unknown to us ? unlike in euro-american contexts , history in sub-saharan africa was not written down by members of cultural communities until colonialism in the late nineteenth and early twentieth centuries . instead of written records , oral narrative was the primary method for collective and personal histories to be passed down from one generation to the next . as these spoken histories were passed down , they were changed and adapted to reflect their times . the changing nature of oral narrative is like a highly complex game of telephone , where the words can be changed and often only the spirit of the original meaning is preserved . before being purchased by western collectors and museums , african sculptures served as important historical markers within their communities . the ndop sculptural record helps freeze a moment in time that would otherwise be transformed during its transmission from generation to generation . when we look at these sculptures in museums , it is important to remember that they were created about , and for , individuals . since information and history was transferred orally in africa , sculptural traditions like the ndop can help us gain insight into information about historical individuals and their cultural ideals . the kuba artist the kuba live in the democratic republic of the congo on the southern fringes of the equatorial forest in an area bounded by two rivers called the kasai and sankuru . over a period of three centuries of movement and exchange beginning in the 17th century , this loose confederacy of people formed into a durable kingdom . since that time , the name “ kuba ” largely refers to nineteen unique but related ethnic groups , all of which acknowledge the leadership of the same leader ( nyim ) . the kuba are renowned for a dynamic artistic legacy across media . historically , kuba artists were professional woodcarvers , blacksmiths , and weavers who worked exclusively for the nyim . kuba artists learned their art by becoming apprentices to others who were well-known and accomplished in their community . similar to art traditions in other world cultures , the apprentices imitated or copied early pieces from their teachers until they were skilled enough to develop their own designs . although the names of individual artists were not written down—and are not known to us today—artists were sought after by name and were important to the kuba royal court and beyond . ndop sculpture the ndop statues might be the the most revered of all kuba art forms . the ndop ( literally meaning “ statue ” ) are a genre of figurative wood sculpture that portrays important kuba leaders throughout the eighteenth to twentieth centuries . art historians believe that there are seven ndop statues of historical significance in western museums . these seven are significant because the lives of the nyim they portray were celebrated in oral histories that were recorded and written down by early european visitors , so we know the most about them . you can travel to the british museum in england or the royal museum for central africa in belgium to see ndop . ndop sculptures that are on view at the british museum were brought to europe from africa by hungarian ethnographer emil torday . torday and other early visitors to the kuba court documented oral traditions related to artwork . art historians have since tried to reconstruct and sort out these early accounts ; they use the sculptures themselves to interpret precolonial kuba history . ndop sculpture have rounded contours creating forms that define the head , shoulders and stomach , and also feature a defined collarbone . while the relative naturalism may appear to have been informed by an artist ’ s one-to-one observation of the nyim , ndop sculptures aren ’ t exact likenesses ; they are not actually created from direct observation . instead , cultural conventions and visual precedents guide the artists in making the sculpture . the expression on the face , the position of the body , and the regalia were meant to faithfully represent the ideal of a king—but not an individual king . for example , the facial features of each statue follow sculpting conventions and do not represent features of a specific individual . all figures are sculpted using a one-to-three proportion—the head of the statue was sculpted to be one third the size of the total statue . kuba artists emphasized the head because it was considered to be the seat of intelligence , a valued ideal . how are we able to identify each ndop , then ? there are specific attributes that link each ndop to named individuals . all ndop sculpture would feature a geometric motif and an emblem ( ibol ) , chosen by the nyim when he was installed as a leader and commissioned his ndop . the geometric motif pattern and the ibol served as identifying symbols of his reign and was sculpted in prominent relief on the front of each base . the ibol is a signifier that gives the ndop its particular identity , making it clear who the sculpture portrays and what reign it represents . a drum with a severed hand is the ibol for mishe mishyaang mambul ’ s reign , and that helps us identify the sculpture as his likeness . other styles or conventions that were followed by sculptors of ndop can be found in royal regalia such as belts , armbands , bracelets , shoulder ornaments , and a unique projecting headdress , called a shody . the arms of each ndop extend vertically at either side of the torso , with the left hand grasping the handle of a ceremonial knife ( ikul ) and the right hand resting on the knee . artists decorated the surface of the sculpture by carving representations of what was conventionally worn ; the finely chiseled details correspond to objects that represent the prerogative and prestige of the nyim . the ndop of mishe mishyaang mambul is part of a larger genre of figurative wood sculpture in kuba art . these sculptures were commissioned by kuba leaders or nyim to preserve their accomplishments for posterity . because transmission of knowledge in this part of africa is through oral narrative , names and histories of the past are often lost . the ndop sculptures serve as important markers of cultural ideals . they also reveal a chronological lineage through their visual signifiers . text by roger d. arnold additional reading binkley , david a. and patricia darish . kuba . milan : 5 continents press , 2010 . lagamma , alisa . heroic africans : legendary leaders , iconic sculptures . new york : metropolitan museum of art , 2011 . siegmann , william and joseph adande . african art : a century at the brooklyn museum . new york : prestel , 2009 . vansina , jan. “ recording the oral history of the bakuba. ” journal of african history 1:1 , 1960 , 43 – 61 .
|
text by roger d. arnold additional reading binkley , david a. and patricia darish . kuba . milan : 5 continents press , 2010 .
|
where were ndops displayed at the palaces of kuba kings ?
|
what you should be familiar with before this lesson the gcf ( greatest common factor ) of two or more monomials is the product of all their common prime factors . for example , the gcf of $ 6x $ and $ 4x^2 $ is $ 2x $ . if this is new to you , you 'll want to check out our greatest common factors of monomials article . what you will learn in this lesson in this lesson , you will learn how to factor out common factors from polynomials . the distributive property : $ a ( b+c ) =ab+ac $ to understand how to factor out common factors , we must understand the distributive property . for example , we can use the distributive property to find the product of $ 3x^2 $ and $ 4x+3 $ as shown below : notice how each term in the binomial was multiplied by a common factor of $ \teald { 3x^2 } $ . however , because the distributive property is an equality , the reverse of this process is also true ! if we start with $ 3x^2 ( 4x ) +3x^2 ( 3 ) $ , we can use the distributive property to factor out $ ~\teald { 3x^2 } $ and obtain $ 3x^2 ( 4x+3 ) $ . the resulting expression is in factored form because it is written as a product of two polynomials , whereas the original expression is a two-termed sum . check your understanding factoring out the greatest common factor ( gcf ) to factor the gcf out of a polynomial , we do the following : find the gcf of all the terms in the polynomial . express each term as a product of the gcf and another factor . use the distributive property to factor out the gcf . let 's factor the gcf out of $ 2x^3-6x^2 $ . step 1 : find the gcf $ 2x^3=\maroond2\cdot \goldd { x } \cdot \goldd { x } \cdot x $ $ 6x^2=\maroond2\cdot 3\cdot \goldd { x } \cdot \goldd { x } $ so the gcf of $ 2x^3-6x^2 $ is $ \maroond2 \cdot \goldd x \cdot \goldd x=\teald { 2x^2 } $ . step 2 : express each term as a product of $ \teald { 2x^2 } $ and another factor . $ 2x^3= ( \teald { 2x^2 } ) ( { x } ) $ $ 6x^2= ( \teald { 2x^2 } ) ( { 3 } ) $ so the polynomial can be written as $ 2x^3-6x^2= ( \teald { 2x^2 } ) ( x ) - ( \teald { 2x^2 } ) ( 3 ) $ . step 3 : factor out the gcf now we can apply the distributive property to factor out $ \teald { 2x^2 } $ . verifying our result we can check our factorization by multiplying $ 2x^2 $ back into the polynomial . since this is the same as the original polynomial , our factorization is correct ! check your understanding can we be more efficient ? if you feel comfortable with the process of factoring out the gcf , you can use a faster method : once we know the gcf , the factored form is simply the product of that gcf and the sum of the terms in the original polynomial divided by the gcf . see , for example , how we use this fast method to factor $ 5x^2+10x $ , whose gcf is $ \teald { 5x } $ : $ 5x^2+10x=\teald { 5x } \left ( \dfrac { 5x^2 } { \teald { 5x } } +\dfrac { 10x } { \teald { 5x } } \right ) =\teald { 5x } ( x+2 ) $ factoring out binomial factors the common factor in a polynomial does not have to be a monomial . for example , consider the polynomial $ x ( 2x-1 ) -4 ( 2x-1 ) $ . notice that the binomial $ \teald { 2x-1 } $ is common to both terms . we can factor this out using the distributive property : check your understanding different kinds of factorizations it may seem that we have used the term `` factor '' to describe several different processes : we factored monomials by writing them as a product of other monomials . for example , $ 12x^2= ( 4x ) ( 3x ) $ . we factored the gcf from polynomials using the distributive property . for example , $ 2x^2+12x=2x ( x+6 ) $ . we factored out common binomial factors which resulted in an expression equal to the product of two binomials . for example $ x ( x+1 ) +2 ( x+1 ) = ( x+1 ) ( x+2 ) $ . while we may have used different techniques , in each case we are writing the polynomial as a product of two or more factors . so in all three examples , we indeed factored the polynomial . challenge problems
|
for example , $ 2x^2+12x=2x ( x+6 ) $ . we factored out common binomial factors which resulted in an expression equal to the product of two binomials . for example $ x ( x+1 ) +2 ( x+1 ) = ( x+1 ) ( x+2 ) $ .
|
how would you factor an expression say as 49n squared - 16 to equal a product that has two binomials in parenthesis like this ( ) ( ) ?
|
what you should be familiar with before this lesson the gcf ( greatest common factor ) of two or more monomials is the product of all their common prime factors . for example , the gcf of $ 6x $ and $ 4x^2 $ is $ 2x $ . if this is new to you , you 'll want to check out our greatest common factors of monomials article . what you will learn in this lesson in this lesson , you will learn how to factor out common factors from polynomials . the distributive property : $ a ( b+c ) =ab+ac $ to understand how to factor out common factors , we must understand the distributive property . for example , we can use the distributive property to find the product of $ 3x^2 $ and $ 4x+3 $ as shown below : notice how each term in the binomial was multiplied by a common factor of $ \teald { 3x^2 } $ . however , because the distributive property is an equality , the reverse of this process is also true ! if we start with $ 3x^2 ( 4x ) +3x^2 ( 3 ) $ , we can use the distributive property to factor out $ ~\teald { 3x^2 } $ and obtain $ 3x^2 ( 4x+3 ) $ . the resulting expression is in factored form because it is written as a product of two polynomials , whereas the original expression is a two-termed sum . check your understanding factoring out the greatest common factor ( gcf ) to factor the gcf out of a polynomial , we do the following : find the gcf of all the terms in the polynomial . express each term as a product of the gcf and another factor . use the distributive property to factor out the gcf . let 's factor the gcf out of $ 2x^3-6x^2 $ . step 1 : find the gcf $ 2x^3=\maroond2\cdot \goldd { x } \cdot \goldd { x } \cdot x $ $ 6x^2=\maroond2\cdot 3\cdot \goldd { x } \cdot \goldd { x } $ so the gcf of $ 2x^3-6x^2 $ is $ \maroond2 \cdot \goldd x \cdot \goldd x=\teald { 2x^2 } $ . step 2 : express each term as a product of $ \teald { 2x^2 } $ and another factor . $ 2x^3= ( \teald { 2x^2 } ) ( { x } ) $ $ 6x^2= ( \teald { 2x^2 } ) ( { 3 } ) $ so the polynomial can be written as $ 2x^3-6x^2= ( \teald { 2x^2 } ) ( x ) - ( \teald { 2x^2 } ) ( 3 ) $ . step 3 : factor out the gcf now we can apply the distributive property to factor out $ \teald { 2x^2 } $ . verifying our result we can check our factorization by multiplying $ 2x^2 $ back into the polynomial . since this is the same as the original polynomial , our factorization is correct ! check your understanding can we be more efficient ? if you feel comfortable with the process of factoring out the gcf , you can use a faster method : once we know the gcf , the factored form is simply the product of that gcf and the sum of the terms in the original polynomial divided by the gcf . see , for example , how we use this fast method to factor $ 5x^2+10x $ , whose gcf is $ \teald { 5x } $ : $ 5x^2+10x=\teald { 5x } \left ( \dfrac { 5x^2 } { \teald { 5x } } +\dfrac { 10x } { \teald { 5x } } \right ) =\teald { 5x } ( x+2 ) $ factoring out binomial factors the common factor in a polynomial does not have to be a monomial . for example , consider the polynomial $ x ( 2x-1 ) -4 ( 2x-1 ) $ . notice that the binomial $ \teald { 2x-1 } $ is common to both terms . we can factor this out using the distributive property : check your understanding different kinds of factorizations it may seem that we have used the term `` factor '' to describe several different processes : we factored monomials by writing them as a product of other monomials . for example , $ 12x^2= ( 4x ) ( 3x ) $ . we factored the gcf from polynomials using the distributive property . for example , $ 2x^2+12x=2x ( x+6 ) $ . we factored out common binomial factors which resulted in an expression equal to the product of two binomials . for example $ x ( x+1 ) +2 ( x+1 ) = ( x+1 ) ( x+2 ) $ . while we may have used different techniques , in each case we are writing the polynomial as a product of two or more factors . so in all three examples , we indeed factored the polynomial . challenge problems
|
what you should be familiar with before this lesson the gcf ( greatest common factor ) of two or more monomials is the product of all their common prime factors . for example , the gcf of $ 6x $ and $ 4x^2 $ is $ 2x $ .
|
why ca n't we factor a polynomial by using other common factors ?
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.