Acid Base Titration

Question

To reach the endpoint in titration, a sulfuric acid solution (H₂SO₄) of 15mL requires 22.80mL of 0.1925M NaOH to reach the endpoint in a titration, what is the molarity of the sulfuric acid solution?

My final answer was 0.07M. Please correct me if I am incorrect.

Answer 1

Answer 2

Your answer is half of what it should be. I think you didn't consider that it takes TWO moles NaOH for each ONE mole of H₂SO₄. See below.

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

mols NaOH used = 22.80 ml x 1 L / 1000 ml x 0.1925 mol / L = 0.004389 mols NaOH used

mols H₂SO₄ present = 0.004389 mols NaOH x 1 mol H₂SO₄ / 2 mols NaOH = 0.002195 mols H₂SO₄

Molarity of H₂SO₄ = 0.002195 mols H₂SO₄ / 15 ml x 1000 ml / L = 0.1463 M = 0.15 M (2 sig. figs.)