600 mL of an unknown monoprotic acid was titrated with a standard solution of a 1.0 M base. If it took 40.0 mL of the base to neutralize the acid, what was the H+ ion concentration of the acid in moles per Liter?

Answer 1

How many moles of the base did it take? M x L = 1.0M x 0.040L = 0.04 moles base.
Since the acid is monoprotic (1 H), the moles acid must be the same so you have 0.04 moles acid in the sample, which was 600 mL.
(H^+) M = moles/L = 0.040/0.600L