Calculating the pH When a Common Ion Is Involved

For the generic equilibriumHA(aq) ? H+(aq) + A?(aq) , which of thesestatements is true?

For the generic equilibrium rm HA (aq) ~ rightleftharpoons~rmH^+ (aq)~+~A^-(aq), which of these statements is true?

1	If you add the soluble salt KA to a solution of HA that is atequilibrium, the pH would increase.
2	If you add the soluble salt KA to a solution of HA that is atequilibrium, the concentration of HA would decrease.
3	If you add the soluble salt KA to a solution of HA that is atequilibrium, the concentration of A? would decrease.
4	The equilibrium constant for this reaction changes as the pHchanges.