Question

If 26.0 mL of 0.110 M NaOH was needed to neutralize 10.0 mL of an unknown sulfuric acid (H2SO4) solution, what is the concentration of the H2SO4? (Note: sulfuric acid is “diprotic” meaning there are 2 acidic protons. This is important when balancing the reaction)

Answer 1

2NaOH + H2SO4 ==> Na2SO4 + 2H2O
millimoles NaOH = mL x M = 26.0 x 0.110 = 2.86
From the equation you see 2 mols NaOH = 1 mol H2SO4; therefore, 2,86 mmols NaOH is equal to 1/2 * 2.86 = 1.43 mmoles H2SO4.
Then M H2SO4 = millimoles H2SO4/mL H2SO4 = ? M