If you have 0.2 M of NaC7H4ClO2 with a pH of 8.65, what is the pH of 0.2 M of HC7H4ClO2?

Answer 1

Let's just call this acid HA. It's the salt that is hydrolyzing, so
A^- + HOH ==> HA + OH^-

Kb = Kw/Ka = (HA)(OH^-)/(A^-)
You know Kw, Ka is what you want, (HA)=(OH^-) and you can get the OH from the pH. After you find Ka, use that as you would a weak acid ionization.
HA ==> H^+ + A^-
Ka = (H^+)(A^-)/(HA)
Do an ICE chart for the HA and solve for H^+ and pH. Post your work if you get stuck.

Answer 2

im sorry i don't understand could you please go into a little more detail.. i broke it up into NaC7H4ClO2 --> Na+ and C7H4ClO2
then did C7H4ClO2 + H2O --> ?