21 mL It required 42.35 mL of H2SO4 to neutralize 21.17 mL of 0.5000 M NaOH. Calculate the concentration of H2SO4

The balanced equation for the above reaction is

2NaOH + H₂SO₄ - - - > Na₂SO₄ + 2H₂O

stoichiometry of NaOH to H₂SO₄ is 2:1

number of NaOH moles required-0.5000 M / 1000 mL/L x 21.17 mL = 0.010585 mol

According to stoichiometry, acid moles required are 1/2 of the base moles reacted

Therefore number of H₂SO₄ moles reacted - 0.010585 / 2 mol

Number of moles in 42.35 mL of H₂SO₄ - 0.010585 / 2 mol

Therefore in 1 L solution - (0.010585) / 2 / 42.35 mL x 1000 mL/L = 0.125 M

Molarity of H₂SO₄ - 0.125 M