Question

A solution of 0.172 M NaOH is used to neutralize 27.0 mL of a H2SO4 solution.

Part A

If 30.6 mL of the NaOH solution is required to reach the endpoint, what is the molarity of the H2SO4 solution?

H2SO4(aq)+2NaOH(aq)→2H2O(l)+Na2SO4(aq)

Express your answer with the appropriate units.

molarity =	???

Enter your answer using dimensions of chemical concentration

Answer 1

Number of moles of NaOH utilized , n = Molarity x volume in L

                                                       = 0.172 M x (30.6/1000) L

                                                       = 5.26x10^-3 mol

The balanced equation is :

H₂SO₄(aq) + 2NaOH(aq)   → 2H₂O(l) + Na₂SO₄(aq)

According to the balanced equation ,.

2 moles of NaOH requires 1 mole of H₂SO₄

5.26x10^-3 mol of NaOH requires M mole of H₂SO₄

M = ( 5.26x10^-3 x1) / 2

   = 2.63 x10^-3 mol

Given that the volume of H₂SO₄ is 27.0 mL = 0.027 L

So Molarity of H₂SO₄ is , M = number of moles of H₂SO₄ reacted / volume of H₂SO₄ in mL

                                        = (2.63 x10^-3 mol) / 0.027 L

                                       = 0.097 M

Therefore the molarity of unknown sulphuric acid solution is 0.097 M