A Chemist titrates 100.0 mL of a 0.1485 M hypochlorous acid (HClO) solution with 0.1204 M KOH solution at 25° C. Calculate the pH at the equivalence. The pKa of hypochlorous acid is 7.50.
Round the answer to 2 decimal places.
Note for advanced students: you may assume the total volume of the solution equals to the initial plus the volume of KOH solution added.
Calculating the exact pH is, as usual in titration problems, a solution stoichiometry (moles/molarity/volume) problem followed by an equilibrium composition problem.
- First, you need to calculate the molarity of HCl
- after the titration reaction has run. This is the stoichiometry problem.
- Then you can set up a reaction table and use the K
- a equation for HCl to calculate the equilibrium molarity of KOH +This is the equilibrium problem