Friday, November 21, 2008
Fri-day 1
AP Chem- we further discussed constant pressure calorimetry, the experimental error that is built-in to these measurements (i.e. no container is a perfect insulator so some, but NOT much, energy is exchanged with the surroundings outside of the container.
We then did the long version of Hess's Law, which solely relies on the fact that Enthalpy, H, is a STATE function; that fact enables us to just algebraically manipulate several equations that ADD up to the NET equation that we desire.
But wait...
Using the STRICT definition of "heat of formation", for which we MUST know the MOST STABLE FORM and PHASE of a given substance at 298K and 1atm, we can then use the "easy/brief" version of Hess's Law, which will ALWAYS get you the same net answer as the longer version of Hess's Law.
We looked at various common elements and discussed their most stable form and phase at 298K and 1 atm and then we applied Hess's (brief) law to the "thermite reaction".
We then started a mini-lab in which we are forced to use our knowledge to assess the contents of four aqueous solutions that were "mislabeled".
Bio 6/7- we discussed the light-dependent (granum) reactions and the light-independent reactions (stroma) of photosynthesis. We then derived the various factors that must influence the rate of photosynthesis. By looking at the REACTANTS for photosynthesis (including the light energy and the enzymes involved), we figured out that altering the quantity of a given reactant MUST influence the rate of photosynthesis.
We then tested one of those factors (light intensity) in a rate of photosynthesis lab.
Bio 8 - we discussed the light-dependent (granum) reactions and the light-independent reactions (stroma) of photosynthesis. We then derived the various factors that must influence the rate of photosynthesis. By looking at the REACTANTS for photosynthesis (including the light energy and the enzymes involved), we figured out that altering the quantity of a given reactant MUST influence the rate of photosynthesis.
We then did the long version of Hess's Law, which solely relies on the fact that Enthalpy, H, is a STATE function; that fact enables us to just algebraically manipulate several equations that ADD up to the NET equation that we desire.
But wait...
Using the STRICT definition of "heat of formation", for which we MUST know the MOST STABLE FORM and PHASE of a given substance at 298K and 1atm, we can then use the "easy/brief" version of Hess's Law, which will ALWAYS get you the same net answer as the longer version of Hess's Law.
We looked at various common elements and discussed their most stable form and phase at 298K and 1 atm and then we applied Hess's (brief) law to the "thermite reaction".
We then started a mini-lab in which we are forced to use our knowledge to assess the contents of four aqueous solutions that were "mislabeled".
Bio 6/7- we discussed the light-dependent (granum) reactions and the light-independent reactions (stroma) of photosynthesis. We then derived the various factors that must influence the rate of photosynthesis. By looking at the REACTANTS for photosynthesis (including the light energy and the enzymes involved), we figured out that altering the quantity of a given reactant MUST influence the rate of photosynthesis.
We then tested one of those factors (light intensity) in a rate of photosynthesis lab.
Bio 8 - we discussed the light-dependent (granum) reactions and the light-independent reactions (stroma) of photosynthesis. We then derived the various factors that must influence the rate of photosynthesis. By looking at the REACTANTS for photosynthesis (including the light energy and the enzymes involved), we figured out that altering the quantity of a given reactant MUST influence the rate of photosynthesis.
# posted by C @ 1:03 PM 
