A solution containing 0.0158 M maleic acid and 0.0226 M disodium maleate. The Ka values for maleic acid are 1.20 × 10-2 (Ka1) and 5.37 × 10-7 (Ka2). What is the pH of the solution ?

Question

A solution containing 0.0158 M maleic acid and 0.0226 M disodium maleate. The Ka values for maleic acid are 1.20 × 10-2 (Ka1) and 5.37 × 10-7 (Ka2).  What is the pH of the solution ?