Monday, January 26, 2009
Mon-Day 2
AP Chem- we showed how to graphically determine the rate constant for a given reaction given the changing rate of reaction vs. the concentration of a given reactant or product to a particular POWER/EXPONENT. The slope of the line from this plot is the value of the rate constant and the ONLY factor that can CHANGE the rate constant for a given reaction is the TEMPERATURE.
The exponent used in order to yield a straight line for the plot tells the ORDER or MOLECULARITY of that PARTICULAR reactant in the "rate-determining" step of the reaction mechanism. That means that if rate = k [A]^2, there must be TWO "A" molecules involved in the collision in the particular step of the reaction mechanism that essentially determines the RATE of the whole reaction (some steps occur extremely quickly, others slowly; it's the slow steps that determine the rate of the overall reaction, as we will discuss tomorrow).
Related to the above, we discussed how to write a rate law from PROPOSED elementary steps of a reaction mechanism.
For example, the elementary step A + C --> Q would have a rate law of : rate = k [A] [C]
showing an overall ORDER or MOLECULARITY of 2 but an order/molecularity of 1 for EACH of A and C (they are both to the 1st power).
Basically, we are in the midst of relating a proposed mechanism for a given reaction to its EXPECTED mathematical rate law; we then COMPARE the expected mathematical rate law to the ACTUAL experimental data. I will show you how to write a rate law from actual experimental data (always 3 or more experimental trials); if you have facility with exponents, then you might actually enjoy the slight deciphering of the experimental data required.
Bio 6- we began the respiratory system part of our unit by discussing the structure and function of each component. We saw how each part of the respiratory system aids in increasing the diffusion of oxygen into the blood: the nasal passages help to filter, warm, and moisten the oxygen/air, the epiglottis prevents the clogging of the lungs with food or drink, the trachea remains sturdy due to its rings of cartilage (it also has additional cilia for more filtration especially of the air that enters through the mouth), the alveoli are rounded and are in bunches surrounded by beds/webs of capillaries to maximize surface area for oxygen and carbon dioxide exchange.
We briefly discussed the breathing mechanism, which we will elaborate on tomorrow.
Bio 7/8- we finished the circulatory system by discussing the "fluid" that is pumped through the vessels by the heart; that fluid is the blood, which is composed of red blood cells (erythrocytes), white blood cells, platelets, and plasma. Blood is the connective tissue that links all parts of the body.
The red blood cells, which contain no nucleus, transport oxygen to body cells from the lungs and transport carbon dioxide from body cells to be excreted by the lungs.
There are several different specific white blood cells, but they all are involved in your immune system, helping your body to maintain homeostasis by preventing harmful substances, cells, or organisms from entering or affecting your body.
The platelets help to form blood clots to prevent bleeding from broken blood vessels; you have a CLOSED circulatory system so all of the blood is ENCLOSED within vessels that must remain free from holes or punctures to contain the blood; platelets aid in plugging up any breaches in these vessels.
The plasma contains dissolved and undissolved (mixed) enzymes, vitamins, minerals, sugars, fatty acids, amino acids, hormones, nucleotides that are transported to the various cells of the body.
We then began our focus on the system that works in cooperation with the circulatory system:
the RESPIRATORY system.
We recalled the two types of CELLULAR respiration: aerobic and anaerobic.
The oxygen needed by cells (mitochondria) for aerobic respiration is obtained by the functioning of the respiratory system and transported to the cells via the circulatory system.
We discussed the structure and function of each component of the respiratory system. We saw how each part of the respiratory system aids in increasing the diffusion of oxygen into the blood: the nasal passages help to filter, warm, and moisten the oxygen/air, the epiglottis prevents the clogging of the lungs with food or drink, the trachea remains sturdy due to its rings of cartilage (it also has additional cilia for more filtration especially of the air that enters through the mouth), the alveoli are rounded and are in bunches surrounded by beds/webs of capillaries to maximize surface area for oxygen and carbon dioxide exchange.
The exponent used in order to yield a straight line for the plot tells the ORDER or MOLECULARITY of that PARTICULAR reactant in the "rate-determining" step of the reaction mechanism. That means that if rate = k [A]^2, there must be TWO "A" molecules involved in the collision in the particular step of the reaction mechanism that essentially determines the RATE of the whole reaction (some steps occur extremely quickly, others slowly; it's the slow steps that determine the rate of the overall reaction, as we will discuss tomorrow).
Related to the above, we discussed how to write a rate law from PROPOSED elementary steps of a reaction mechanism.
For example, the elementary step A + C --> Q would have a rate law of : rate = k [A] [C]
showing an overall ORDER or MOLECULARITY of 2 but an order/molecularity of 1 for EACH of A and C (they are both to the 1st power).
Basically, we are in the midst of relating a proposed mechanism for a given reaction to its EXPECTED mathematical rate law; we then COMPARE the expected mathematical rate law to the ACTUAL experimental data. I will show you how to write a rate law from actual experimental data (always 3 or more experimental trials); if you have facility with exponents, then you might actually enjoy the slight deciphering of the experimental data required.
Bio 6- we began the respiratory system part of our unit by discussing the structure and function of each component. We saw how each part of the respiratory system aids in increasing the diffusion of oxygen into the blood: the nasal passages help to filter, warm, and moisten the oxygen/air, the epiglottis prevents the clogging of the lungs with food or drink, the trachea remains sturdy due to its rings of cartilage (it also has additional cilia for more filtration especially of the air that enters through the mouth), the alveoli are rounded and are in bunches surrounded by beds/webs of capillaries to maximize surface area for oxygen and carbon dioxide exchange.
We briefly discussed the breathing mechanism, which we will elaborate on tomorrow.
Bio 7/8- we finished the circulatory system by discussing the "fluid" that is pumped through the vessels by the heart; that fluid is the blood, which is composed of red blood cells (erythrocytes), white blood cells, platelets, and plasma. Blood is the connective tissue that links all parts of the body.
The red blood cells, which contain no nucleus, transport oxygen to body cells from the lungs and transport carbon dioxide from body cells to be excreted by the lungs.
There are several different specific white blood cells, but they all are involved in your immune system, helping your body to maintain homeostasis by preventing harmful substances, cells, or organisms from entering or affecting your body.
The platelets help to form blood clots to prevent bleeding from broken blood vessels; you have a CLOSED circulatory system so all of the blood is ENCLOSED within vessels that must remain free from holes or punctures to contain the blood; platelets aid in plugging up any breaches in these vessels.
The plasma contains dissolved and undissolved (mixed) enzymes, vitamins, minerals, sugars, fatty acids, amino acids, hormones, nucleotides that are transported to the various cells of the body.
We then began our focus on the system that works in cooperation with the circulatory system:
the RESPIRATORY system.
We recalled the two types of CELLULAR respiration: aerobic and anaerobic.
The oxygen needed by cells (mitochondria) for aerobic respiration is obtained by the functioning of the respiratory system and transported to the cells via the circulatory system.
We discussed the structure and function of each component of the respiratory system. We saw how each part of the respiratory system aids in increasing the diffusion of oxygen into the blood: the nasal passages help to filter, warm, and moisten the oxygen/air, the epiglottis prevents the clogging of the lungs with food or drink, the trachea remains sturdy due to its rings of cartilage (it also has additional cilia for more filtration especially of the air that enters through the mouth), the alveoli are rounded and are in bunches surrounded by beds/webs of capillaries to maximize surface area for oxygen and carbon dioxide exchange.
# posted by C @ 11:53 AM 
