The pKa of hypochlorous acid is 7.530. A 51.0 mL solution of 0.138 M sodium hypochlorite (NaOCl) is titrated with 0.338 M HCl. Calculate the pH of the solution after the addition of 6.58 mL of 0.338 M HCl. Calculate the pH of the solution after the additon of 21.9 mL of 0.338 M HCl. Calculate the pH of the solution at the equivalence point with 0.338 M HCl.