Friday, January 23, 2009
Thurs-Day 2
AP Chem- we began the Kinetics unit, which involves the rates of chemical reactions and the mechanisms by which they occur.
We discussed two of the factors that will affect the EFFECTIVE collision rate/frequency; the effective collision rate is possibly affected by THREE factors:
1. collision frequency
2. orientation of collisions (not all bond breakage will result in the formation of the specific STABLE main product of the given reaction)
3. force/KE of the collision
NOTHING else need be considered so ALL explanations of kinetics should address EACH of the above three factors.
The NATURE (covalently bonded molecules or solvated ions, for example) of the reactants CANNOT be altered for a given reaction but the strength of either the covalent or ionic bonds OR the strength of the intermolecular attractions or ion-dipole attractions will determine the fraction of molecules that have sufficient KE to overcome the activation energy at a given temperature. Naturally, the stronger the bonds or attractions within or between the reactant particles, the greater the activation energy that must be overcome to achieve an EFFECTIVE (bond or attraction- breaking) collision.
The CONCENTRATION of the reactants is important because an increase in reactant particle concentration will increase the collision frequency among the reactant particles though this factor will not change the PERCENTAGE of effective collisions (due to proper orientation or sufficient KE of collision), the overall NUMBER of effective collisions per second will increase.
Bio 6- We reviewed the structure and function of the heart. We noted that the heart has four chambers: two atria and two ventricles. We described the heart's pumping action: the two atria simultaneously beat, sending deoxygenated blood from the right atrium through the open right A-V valve to the right ventricle just below it while sending freshly oxygenated blood from the left atrium to the left ventricle. Then, in about one second, the two ventricles simultaneously contract, sending deoxygenated blood from the right ventricle to the lungs via the pulmonary arteries while oxygenated blood gets pumped from the left ventricle to the aorta.
The heartbeat that is heard ("lub-dub" sound) is the result of the A-V valves slamming shut to avoid backflow of blood from ventricles to atria after the atria have contracted ("lub") and then the "semilunar"/mitral valves strongly slamming shut ("dub") to avoid backflow of blood from aorta to left ventricle or from pulmonary arteries to right ventricle after the ventricles have contracted.
We discussed the three types/regions of blood circulation, each with a particular purpose:
systemic circulation: the most far-reaching circulation of blood throughout the body from the heart to aorta to arteries, arterioles, capillaries, venules, veins and back to the heart.
coronary circulation: the sending of blood FROM the heart TO the heart via coronary arteries; blockage of these arteries causes a heart attack.
pulmonary (lung) circulation: the transport of blood from heart to lungs and back to the heart so that oxygen can diffuse from the lungs to the red blood cells and that carbon dioxide can be released from the blood cells and diffuse into the lungs.
Bio 7/8- We reviewed the structure and function of the heart. We noted that the heart has four chambers: two atria and two ventricles. We described the heart's pumping action: the two atria simultaneously beat, sending deoxygenated blood from the right atrium through the open right A-V valve to the right ventricle just below it while sending freshly oxygenated blood from the left atrium to the left ventricle. Then, in about one second, the two ventricles simultaneously contract, sending deoxygenated blood from the right ventricle to the lungs via the pulmonary arteries while oxygenated blood gets pumped from the left ventricle to the aorta.
The heartbeat that is heard ("lub-dub" sound) is the result of the A-V valves slamming shut to avoid backflow of blood from ventricles to atria after the atria have contracted ("lub") and then the "semilunar"/mitral valves strongly slamming shut ("dub") to avoid backflow of blood from aorta to left ventricle or from pulmonary arteries to right ventricle after the ventricles have contracted.
We discussed the three types/regions of blood circulation, each with a particular purpose:
systemic circulation: the most far-reaching circulation of blood throughout the body from the heart to aorta to arteries, arterioles, capillaries, venules, veins and back to the heart.
coronary circulation: the sending of blood FROM the heart TO the heart via coronary arteries; blockage of these arteries causes a heart attack.
pulmonary (lung) circulation: the transport of blood from heart to lungs and back to the heart so that oxygen can diffuse from the lungs to the red blood cells and that carbon dioxide can be released from the blood cells and diffuse into the lungs.
We then began a lab in which we measured the effect of increased exercise/activity on the pulse rate. We will develop the discussion of this lab as we discuss the interaction of the respiratory and circulatory systems.
We discussed two of the factors that will affect the EFFECTIVE collision rate/frequency; the effective collision rate is possibly affected by THREE factors:
1. collision frequency
2. orientation of collisions (not all bond breakage will result in the formation of the specific STABLE main product of the given reaction)
3. force/KE of the collision
NOTHING else need be considered so ALL explanations of kinetics should address EACH of the above three factors.
The NATURE (covalently bonded molecules or solvated ions, for example) of the reactants CANNOT be altered for a given reaction but the strength of either the covalent or ionic bonds OR the strength of the intermolecular attractions or ion-dipole attractions will determine the fraction of molecules that have sufficient KE to overcome the activation energy at a given temperature. Naturally, the stronger the bonds or attractions within or between the reactant particles, the greater the activation energy that must be overcome to achieve an EFFECTIVE (bond or attraction- breaking) collision.
The CONCENTRATION of the reactants is important because an increase in reactant particle concentration will increase the collision frequency among the reactant particles though this factor will not change the PERCENTAGE of effective collisions (due to proper orientation or sufficient KE of collision), the overall NUMBER of effective collisions per second will increase.
Bio 6- We reviewed the structure and function of the heart. We noted that the heart has four chambers: two atria and two ventricles. We described the heart's pumping action: the two atria simultaneously beat, sending deoxygenated blood from the right atrium through the open right A-V valve to the right ventricle just below it while sending freshly oxygenated blood from the left atrium to the left ventricle. Then, in about one second, the two ventricles simultaneously contract, sending deoxygenated blood from the right ventricle to the lungs via the pulmonary arteries while oxygenated blood gets pumped from the left ventricle to the aorta.
The heartbeat that is heard ("lub-dub" sound) is the result of the A-V valves slamming shut to avoid backflow of blood from ventricles to atria after the atria have contracted ("lub") and then the "semilunar"/mitral valves strongly slamming shut ("dub") to avoid backflow of blood from aorta to left ventricle or from pulmonary arteries to right ventricle after the ventricles have contracted.
We discussed the three types/regions of blood circulation, each with a particular purpose:
systemic circulation: the most far-reaching circulation of blood throughout the body from the heart to aorta to arteries, arterioles, capillaries, venules, veins and back to the heart.
coronary circulation: the sending of blood FROM the heart TO the heart via coronary arteries; blockage of these arteries causes a heart attack.
pulmonary (lung) circulation: the transport of blood from heart to lungs and back to the heart so that oxygen can diffuse from the lungs to the red blood cells and that carbon dioxide can be released from the blood cells and diffuse into the lungs.
Bio 7/8- We reviewed the structure and function of the heart. We noted that the heart has four chambers: two atria and two ventricles. We described the heart's pumping action: the two atria simultaneously beat, sending deoxygenated blood from the right atrium through the open right A-V valve to the right ventricle just below it while sending freshly oxygenated blood from the left atrium to the left ventricle. Then, in about one second, the two ventricles simultaneously contract, sending deoxygenated blood from the right ventricle to the lungs via the pulmonary arteries while oxygenated blood gets pumped from the left ventricle to the aorta.
The heartbeat that is heard ("lub-dub" sound) is the result of the A-V valves slamming shut to avoid backflow of blood from ventricles to atria after the atria have contracted ("lub") and then the "semilunar"/mitral valves strongly slamming shut ("dub") to avoid backflow of blood from aorta to left ventricle or from pulmonary arteries to right ventricle after the ventricles have contracted.
We discussed the three types/regions of blood circulation, each with a particular purpose:
systemic circulation: the most far-reaching circulation of blood throughout the body from the heart to aorta to arteries, arterioles, capillaries, venules, veins and back to the heart.
coronary circulation: the sending of blood FROM the heart TO the heart via coronary arteries; blockage of these arteries causes a heart attack.
pulmonary (lung) circulation: the transport of blood from heart to lungs and back to the heart so that oxygen can diffuse from the lungs to the red blood cells and that carbon dioxide can be released from the blood cells and diffuse into the lungs.
We then began a lab in which we measured the effect of increased exercise/activity on the pulse rate. We will develop the discussion of this lab as we discuss the interaction of the respiratory and circulatory systems.
# posted by C @ 3:31 PM 
