A5.00-g quantity of a diprotic acid was dissolved in water and made up to exactly 250 mL.

Question:

A5.00-g quantity of a diprotic acid was dissolved in water and made up to exactly 250 mL. Calculate the molar mass of the acid if 25.0 mL of this solution required 11.1 mL of 1.00 M KOH for neutralization.
Assume that both protons of the acid were titrated.