A particular weak acid (HA) with a Ka of 2.0e-5 is 75% titrated with a strong base to produce a buffer solution. What is the pH of this final solution? Show all work.

Answer 1

Use the HH equation.
I would start with any convenient number for the initial concentration of HA. Any number will work but I would choose 1 to make it easy.
So if we start with 1M HA it will be 0.25 at 75% titrated and the salt (the base) will be what? Plug those values into the HH equation and solve for pH.