Question

A 30.0 mL sample of 0.150 M H_2SO_4 is placed into a 125 mL Erlenmeyer flask and a 25 mL buret is filled with 0.250 M KOH. Calculate the volume of base required to reach the equivalence point. Remember you must not use M_1V_1 = M_2V_2 for this calculation.

Answer 1

no. of mole = molarity $\times$ volume of solution in liter

no. of mole of H₂SO₄ = 0.150 $\times$ 0.030 = 0.0045 mole

neutrilization reaction between KOH and H₂SO₄ is

2KOH + H₂SO₄   $\rightarrow$   2H₂O + K₂SO₄

According to reaction 2 mole of KOH neutilize 1 mole of H₂SO₄ therefore to neutrilize 0.0045 mole of H₂SO₄ require KOH = 0.0045 $\times$ 2 = 0.0090 mole of KOH

volume of solution in liter = no.of mole / molarity

volume of NaOH = 0.0090 / 0.250 = 0.036 liter = 36 ml

36 ml NaOH required