Question

For the diprotic weak acid H2A, Ka1 = 3.1 × 10-5 and Ka2 = 6.6 × 10-7. What is the pH of a 0.0600 M solution of H2A? What are the equilibrium concentrations of H2A and A2– in this solution?

Answer 1

You need to set up a series of equations, one for each dissociation. Then use ICE boxes to solve for the unkonwn concentrations using the different KA values.