Question

The common-ion effect is defined as the shift in an ionic equilibrium produced by the addition of a solute that provides an ion common to the equilibrium. Compare the following two solutions:

Solution 1: 0.100 M C2H4O2
Solution 2: 5mL 0.100 M C2H4O2 + 5mL 0.100 M HCl

The [H3O+] ions from the strong acid in solution 2 force the equilibrium C2H4O2 ? H2O + C2H3O2- almost completely to the left. As a result, the pH is determined by the H3O+ ions from the strong acid. Calculate the pH of Solution 1 (ka = 1.738 x 10-5) and 2 (assume HCl dominate for calculation)

What is the pH level for Solution 1 and Solution 2?