Titration of 664 mg of a pure organic carboxylic acid, H2A, showed a rapid change in pH at 40.00 mL and at 80.00 mL of 0.100 M NaOH titrant. When 40.00 mL of NaOH was added, the pH was 5.85, and at 60.00 mL of NaOH the pH was 8.08. What is the molecular weight of H2A and what are the approximate values of K1 and K2.