Consider the equilibrium: H2O(l) + HC2H3O2 ⇌ H3O+ + C2H3O2-
( All species are aqueous)
Why will the addition of NaOH to a solution of acetic acid cause the concentration of the acetate ion to increase?
1 answer
More Le Chatelier's Principle. Adding NaOH neutralizes the H3O^+. Decreasing H3O^+ means the equilibrium must shift to the right in order to undo what you just did to the reaction and that increases the acetate.