Determine the pH of a 0.5M solution of oxalic acid, using only Ka1.?

H2C2O4 (aq) +H2O(l) ⇌ HC2O4-(aq) + H3O+(aq)
HC2O4-(aq) +H2O(l) ⇌ C2O4-2(aq) + H3O+(aq)


Name: Oxalic
Formula: H2C2O4
Ka1: 5.9 X 10^-2
Ka2: 6.4 x 10^-5


1. Determine the pH of a 0.5M solution of oxalic acid, using only Ka1.


2. Using your answers for the concentration of each ion from question 1, what is
the new pH when you apply the second equation using Ka2?


Can someone help me with these problems. I am not really sure where to begin.