[Fzang]

The problem sounds more or less like this (translated)

"Oxalic acid H2C2O4 is a diprotic acid with the acidity constants K(1)=10^-1.23 M and K(2)=10^-4.19 M. The ionization constant of water is Kv=10^-14.00 M²

Calculate the concentrations of C2O4^2-, HC2O4^-, Na⁺ and OH^- in a 0.01 M solution of Na2C2O4. Finally, calculate the pH of the solution. Only the equilibrium is taken into consideration.

C2O4^2- + H2O <--> HC2O4^- + OH^-"


Can someone help me get started?

[Borek]

Calculate K_b, assume C₂O₄^2- is a weak base.

[Fzang]

Kb = Kw/K(2), so

Kb = 1.55 * 10^-10

I'm sorry, still lost. 

[rabolisk]

How does Kb relate to the reaction you wrote? Your value is correct, but what does it mean?

[Vidya]

Kb = Kw/K(2), so

Kb = 1.55 * 10-10

now you can set up ICE table