"A student was given a .1 M solution of an unknown diprotic acid, H2A, and asked to determine the Ka1 and Ka2 values. The student titrated 50.0 mL of the .1 M H2A with .1 M NaOH. After 25mL of NaOH was added, the pH of the resulting solution was 6.7. After 50 mL of NaOH was added, the pH of the resulting solution was 8.00. What are the kalues of Ka1 and Ka2?" I'm a bit lost with this problem. Are the volumes that are given mean it has reached the stoichiometric point? If so, I think I can figure that out just through equilibrium expressions, but I'm not entirely sure. Any help would be appreciated. Thanks!