In chemsitry, we are doing Ka, Kb, and Ksp. This includes the awesomeness of RICE tables--often called ICE tables but our teacher likes to include the R reaction. So, basically, we are using:
Ka = [product 1][H3O+]/[reactant]
Kb = [product 1][OH-]/[reactant]
Kw = Ka times Kb =1.0 X 10^-14
Ka is the equilibrium constant for weak acids
Kb is the equilibrium constant for weak bases
Kw is the constant of water and it is the multiplication of Ka by Kb
pH = -log[H3O+]
pOH = -log[OH-]
pH + pOH = 14
pH of 7 is neutral, below 7 is acidic, above 7 is basic
(p stands for -log)
pH = pKa - log(acid/base)
and Ksp is difficult to explain. It is determined by solubility. Essentially, it tells what concentration of ion you have at equilibrium. It is used for weak electrolytes.
Billy, I thought you might enjoy this. I dont want to get into the reactant -x, product + x, common ions, titrations, or pH and common ion Ksp.
We are having a test tomorrow. I think the teacher said it would be like 12 questions (but a good number will have a,b, c, d, e, f extras to the problems. So its really like a 30/40 question test), and I think I am going to struggle with it.
Chemistry was not one of my stronger subjects - except for a while in Year 9 when I was in love with this black haired boy who happened to be good at the subject!
ReplyDeleteGood luck!
Hahaha, by now I'm sure you've completely demolished the test, but good luck anyway. I'm beginning to prepare my class for their big June exam, so I've just given them a really hard test in a ridiculously short period of time, on volumetric and gravimetric analysis. (Theory: when June rolls around they'll be ready for anything). I then spend the next week one-on-one with them convincing them that actually 60% is a very good mark, now you know what to expect, etc etc. It's hard, but being an asshole works.
ReplyDeleteOh, and I'm with your teacher on the R line. Damn you students who forget the coefficients. Almost as bad as getting the mass formula wrong.
It wasn't a terrible test. I think it was about 30 questions. Of those questions, I know that I missed 2, maybe 5. But 5 would be the most. If I missed 2, that is about a 94%. If I missed 5, that could be about an 84 at the lowest. (They are each weighted differently.) My idea of success on an in-class test is above an 80. So, I have definitely succeeded. I know the ones I missed/might have missed because i talked to her after school and we looked over the test.
ReplyDeleteIn highschool Chemistry was one of my favourite subjects. Its a pity that since then, i've sort of forgotten most of what i've learnt.
ReplyDeletegood luck with your exam results.