Calculate the concentration of this sulfuric acid solution.

Question

A fine titration is performed on a different sulfuric acid sample. When a 12.00 mL sample of the sulfuric acid is titrated with 0.241 M sodium hydroxide to the endpoint, the initial and final buret readings were 0.20 mL and 41.45 mL, respectively. Calculate the concentration of this sulfuric acid solution.

Answer 1

H₂SO₄ + 2NaOH ==> Na₂SO₄ + 2H₂O ... balanced equation for titration

Volume of 0.241 M NaOH used = 41.45 ml - 0.20 ml = 41.25 ml = 0.04125 L

moles NaOH used = 0.04125 L x 0.241 mol/L = 0.00994 moles NaOH

moles H₂SO₄ present = 0.00994 mols NaOH x 1 mol H₂SO₄ / 2 mols NaOH = 0.00497 mols H₂SO₄

volume H₂SO₄ = 12.00 ml x 1 L / 1000 ml = 0.01200 L

Molarity of H₂SO₄ = 0.00497 mols / 0.01200 L = 0.414 M