[SOLVED] pH of buffer solution 1. The problem statement, all variables and given/known data Calculate the pH of a solution made by mixing 750 mL 1.00 M NH4+Cl and 250 mL 1.00 M NaOH 3. The attempt at a solution NH4+ will react with H2O to form NH3 and H2O+. If my calculations are correct, [H+] after the reaction will be 2.07E-5. Then H+ will react with OH-. But since there's almost no H+ compared to NO-, this reaction is irrelevant. The pOH is therefore pOH = -log [0.25], and the pH is 13.4 which is wrong. What's my mistake(s)?