Tuesday, April 24, 2007
Tues-Day 6
AP- we had our Electro exam today; tomorrow, we finally begin our formal AP exam review during which I will emphasize test-taking skills and, of course, exam content knowledge. Download and preview the part II exam. We will likely do our first part I on Friday. Here is how these classes "work": you will have a part I or part II exam to preview/analyze the day before we do the exam in class. Come to class prepared with questions that you dislike/have trouble with/are sketchy about. We will do those immediately in class; then, whichever questions we do not cover, you will do for hw to be handed in the next day. Looking forward to finely honing your skills, which you already have "pre-honed" with your KARMA work. We are now approaching the stretch-drive in our race to a 5. Good times.
Honors: we looked at the various subscripts that are seen on equilibrium constants; these subscripts indicate the type of reaction or process that is occurring. They are all the same old thing though: an equilibrium constant, K.
We then took a more quantitative approach to K in which we MUST use the stoichiometry of the reaction/process as well as the correct K expression. With those two tools, we can solve for the actual equilibrium concentrations in any equilibrium problem.
Tomorrow, we have a test on equilibrium , Le Chatelier's Principle, explanation of Le Chatelier shifts in terms of forward and reverse rates of reaction, and equilibrium constant expressions. Extra help was light today, make sure that you are prepared for this test under timed conditions.
Regents: we discussed entropy/chaos/disorder as a driving force for any reaction/process that occurs naturally/spontaneously. We then did several problems in which we predicted whether the entropy change, delta S, was positive or negative.
The other driving force of a reaction/process is the stability/low potential energy of the products. Thus, exothermic reactions tend to be favored in nature because the products are more stable than the reactants in any exothermic reaction/process.
We then looked at delta G, the change in Gibbs Free Energy. When delta G is negative for any reaction/process, that reaction/process is spontaneous/occurs naturally without the need for a battery or continuous power source.
delta G = delta H - T delta S ; T is in Kelvin.
Honors: we looked at the various subscripts that are seen on equilibrium constants; these subscripts indicate the type of reaction or process that is occurring. They are all the same old thing though: an equilibrium constant, K.
We then took a more quantitative approach to K in which we MUST use the stoichiometry of the reaction/process as well as the correct K expression. With those two tools, we can solve for the actual equilibrium concentrations in any equilibrium problem.
Tomorrow, we have a test on equilibrium , Le Chatelier's Principle, explanation of Le Chatelier shifts in terms of forward and reverse rates of reaction, and equilibrium constant expressions. Extra help was light today, make sure that you are prepared for this test under timed conditions.
Regents: we discussed entropy/chaos/disorder as a driving force for any reaction/process that occurs naturally/spontaneously. We then did several problems in which we predicted whether the entropy change, delta S, was positive or negative.
The other driving force of a reaction/process is the stability/low potential energy of the products. Thus, exothermic reactions tend to be favored in nature because the products are more stable than the reactants in any exothermic reaction/process.
We then looked at delta G, the change in Gibbs Free Energy. When delta G is negative for any reaction/process, that reaction/process is spontaneous/occurs naturally without the need for a battery or continuous power source.
delta G = delta H - T delta S ; T is in Kelvin.
# posted by C @ 5:23 PM 
