Friday, February 6, 2009
Fri-Day 2
AP Chem- Descriptive chem quiz on Monday. It's always a good idea to go over your past descriptive chem sets; you should practice until you can QUICKLY write a perfect set of answers.
IMPORTANT STRATEGY!: you KNOW the reaction types that will be on the quiz so answer the questions as follows:
Decide for yourself WHICH TYPE of reaction you want to write first and then SCAN THE QUESTIONS for that same reaction type! You will be MUCH faster and confident in your answer. For example, if you want to write a gas-forming reaction type first, you then scan EXCLUSIVELY for an ACID mixed with a carbonate, sulfite, or sulfide OR a hydroxide base mixed with an ammonium salt. That's it!
As we begin to prepare for the AP exam, we should try to increase our speed and accuracy on multiple choice questions. The following is a link to a quick multiple choice quiz site; the quizzes are organized by topic:
http://www.adriandingleschemistrypages.com/apquiz.html
The site has very brief (5 questions per set) multiple-choice quizzes sorted by topic. The questions were developed by Prof. Adrian Dingle, who has a yearly AP average of about 4.8 even though he teaches only SOPHOMORES who are taking first year Chem (granted, he teaches at a ritzy private academy in GA where everyone sips tea and talks like Stewie). Most of the quizzes can be completed and scored in two to three minutes! So, practice with these whenever you have some free time or when you are waiting for BBM replies.
Today we began our Equilibrium unit. Equilibrium stems from kinetics in that the RATES of the forward and reverse reactions or processes are equal at equilibrium, thus no further change in the system is observed EVEN THOUGH both the forward and reverse reactions continue forever.
We wrote equilibrium constant EXPRESSIONS in terms of concentrations, Kc, and also in terms of partial pressures, Kp.We also practiced with the formula that interrelates Kc and Kp; that formula is in your reference table. What is NOT in the table is how to calculate "delta n" in that formula; we discussed that in class.We then looked at a heterogeneous solid-gas equilibrium and saw the disturbing and surprising result that AMOUNTS of SOLIDS are IRRELEVANT to EQUILIBRIUM GAS concentrations or pressures because SOLIDS are NOT in the equilibrium constant EXPRESSION; this convention was adopted due to the fact that pure solids or liquids cannot change in concentration (mainly because they are practically incompressible).
p.s. just found a nice interactive, instant-feedback site for some quick rate law practice (you can never get too much of that) here: http://chemistry2.csudh.edu/homework/hwkinetics.html
Bio 6/7- we summarized and condensed the two types of immune response to a pathogen that has penetrated into body tissue cells or into the bloodstream. We noted the COMBINED effectiveness of having a cellular response, during which T-cells directly lyse/kill any infected cells or pathogens that display the SPECIFIC antigen that the T-cells have been "sensitized" to, AND the humoral/antibody response in which MILLIONS of antigen-SPECIFIC (via SHAPE) antibodies are synthesized by EACH B-cell (plasma cell/lymphocyte).
We then discussed diseases of the immune system including allergies, AUTO-immune diseases, and AIDS.
Bio 8- we discussed the two types of immune response to a pathogen that has penetrated into body tissue cells or into the bloodstream. We noted the COMBINED effectiveness of having a cellular response, during which T-cells directly lyse/kill any infected cells or pathogens that display the SPECIFIC antigen that the T-cells have been "sensitized" to, AND the humoral/antibody response in which MILLIONS of antigen-SPECIFIC (via SHAPE) antibodies are synthesized by EACH B-cell (plasma cell/lymphocyte).
IMPORTANT STRATEGY!: you KNOW the reaction types that will be on the quiz so answer the questions as follows:
Decide for yourself WHICH TYPE of reaction you want to write first and then SCAN THE QUESTIONS for that same reaction type! You will be MUCH faster and confident in your answer. For example, if you want to write a gas-forming reaction type first, you then scan EXCLUSIVELY for an ACID mixed with a carbonate, sulfite, or sulfide OR a hydroxide base mixed with an ammonium salt. That's it!
As we begin to prepare for the AP exam, we should try to increase our speed and accuracy on multiple choice questions. The following is a link to a quick multiple choice quiz site; the quizzes are organized by topic:
http://www.adriandingleschemistrypages.com/apquiz.html
The site has very brief (5 questions per set) multiple-choice quizzes sorted by topic. The questions were developed by Prof. Adrian Dingle, who has a yearly AP average of about 4.8 even though he teaches only SOPHOMORES who are taking first year Chem (granted, he teaches at a ritzy private academy in GA where everyone sips tea and talks like Stewie). Most of the quizzes can be completed and scored in two to three minutes! So, practice with these whenever you have some free time or when you are waiting for BBM replies.
Today we began our Equilibrium unit. Equilibrium stems from kinetics in that the RATES of the forward and reverse reactions or processes are equal at equilibrium, thus no further change in the system is observed EVEN THOUGH both the forward and reverse reactions continue forever.
We wrote equilibrium constant EXPRESSIONS in terms of concentrations, Kc, and also in terms of partial pressures, Kp.We also practiced with the formula that interrelates Kc and Kp; that formula is in your reference table. What is NOT in the table is how to calculate "delta n" in that formula; we discussed that in class.We then looked at a heterogeneous solid-gas equilibrium and saw the disturbing and surprising result that AMOUNTS of SOLIDS are IRRELEVANT to EQUILIBRIUM GAS concentrations or pressures because SOLIDS are NOT in the equilibrium constant EXPRESSION; this convention was adopted due to the fact that pure solids or liquids cannot change in concentration (mainly because they are practically incompressible).
p.s. just found a nice interactive, instant-feedback site for some quick rate law practice (you can never get too much of that) here: http://chemistry2.csudh.edu/homework/hwkinetics.html
Bio 6/7- we summarized and condensed the two types of immune response to a pathogen that has penetrated into body tissue cells or into the bloodstream. We noted the COMBINED effectiveness of having a cellular response, during which T-cells directly lyse/kill any infected cells or pathogens that display the SPECIFIC antigen that the T-cells have been "sensitized" to, AND the humoral/antibody response in which MILLIONS of antigen-SPECIFIC (via SHAPE) antibodies are synthesized by EACH B-cell (plasma cell/lymphocyte).
We then discussed diseases of the immune system including allergies, AUTO-immune diseases, and AIDS.
Bio 8- we discussed the two types of immune response to a pathogen that has penetrated into body tissue cells or into the bloodstream. We noted the COMBINED effectiveness of having a cellular response, during which T-cells directly lyse/kill any infected cells or pathogens that display the SPECIFIC antigen that the T-cells have been "sensitized" to, AND the humoral/antibody response in which MILLIONS of antigen-SPECIFIC (via SHAPE) antibodies are synthesized by EACH B-cell (plasma cell/lymphocyte).
# posted by C @ 2:59 PM 
