Calculate the pH for each of the cases in the titration of 25.0 mL of 0.240 M pyridine, C₅H₅N(aq) with 0.240 M HBr(aq). The Kb of pyridine is 1.7×10⁻⁹. After addition of 18.0 mL of HBr, the pH is _______. After addition of 31.0 mL of HBr, the pH is _______.
