Question

A total of 25.0 mL of 0.150 M potassium hydroxide (KOH) was required to neutralize 15.0 mL of sulfuric acid (H2SO4) of unknown concentration. What is the concentration of the sulfuric acid?

Answer 1

The neutralization reaction is expressed as:

2KOH + H2SO4 = K2SO4 + 2H2O

We are given the volume and the concentration of the KOH that is used in the reaction. We use this and the relations from the reaction to determine the concentration of the acid.

0.150 mol KOH / L ( .025 L ) ( 1 mol H2SO4 / 2 mol KOH ) = 0.00188 mol H2SO4

Concentration of acid = 0.00188 mol / .015 = 0.125 M of sulfuric acid