A sample of carbonic acid (0.125 L, 0.165 M, pKa1 = 6.35, pKa2 = 10.33) was titrated with 1.53 M NaOH. Calculate the pH at the following points:
Before the titration. At the 1st midpoint. At the 1st stoichiometric point.
At the 2nd midpoint. At the 2nd stoichiometric point.