Question

A 25.00-ml sample of h2so4 solution of unknown concentration requires 28.27 ml of a 0.185 m koh solution to complete the neutralization reaction. what is the concentration of the unknown h2so4 solution?

Answer 1

the balanced equation for the reaction is as follows
H₂SO₄ + 2KOH ---> K₂SO₄ + 2H₂O
stoichiometry of H₂SO₄ to KOH is 1:2
number of moles of KOH reacted - molarity x volume
number of KOH moles = 0.185 mol/L x 0.02827 L = 0.00523 mol
according to molar ratio of 1:2
2 mol of KOH reacts with 1 mol of H₂SO₄
then 0.00523 mol of KOH requires - 1/2 x 0.00523 mol = 0.00262 mol of H₂SO₄
number of H₂SO₄ moles in 25.00 mL - 0.00262 mol
therefore number of H₂SO₄ moles in 1000 mL - 0.00262 mol / 25.00 mL x 1000 mL/L = 0.105 mol
concentration of H₂SO₄ is 0.105 M