I'm studying for my final exam, and these are the questions I got wrong on the mid term, could anyone help correct me? I know people are against giving answers for homework, so I must add that is now exam period for Universities, so this is only for my further understanding! Thanks so much!
My attempts will be in this format
1)The pH of a 0.2M unknown base X OH is 8.15
10^(-8.15) = 7E-9M
b)What is the % disassociation
(7E-9/0.2M) x 100 = 3.5E-6%
c)What is the Kb of the base?
This one I don't even know where to begin..
2)Calculate the pH of the following solutions
a) 0.10M KCN, Ka (HCN) = 6.2E-10 (Hint: KCN is the salt of a weak acid and a strong base)
x = sqrt(Ka*c) x = sqrt(6.2E-10 * 0.1) = 7.8E-6 -log(7.8E-6) = pH = 5.1