Question

A 29.00 mL sample of an H2SO4 solution of unknown concentration is titrated with a 0.1122 M KOH solution. A volume of 43.22 mL of KOH was required to reach the equivalence point. Part A What is the concentration of the unknown H2SO4 solution? Express your answer using four significant figures.

Answer 1

The balanced chemical equation is as follows:

H2SO4 + 2KOH -------------> K2SO4 + 2 HOH

C = ?         C = 0.1122
V = 29.00 ml V = 43.22 ml

Now calculate the moles of H2SO4 as follows:
moles = C x V

= 0.1122 mol/L x 43.22 mL = 4.84*10^-3 moles

Here 2 mol of KOH need 1 mol of H2SO4

So mol of H2SO4 needed will be 4.85*10^-3 moles x 1/2 = 2.425*10^-3 moles

Now that we have both the moles and volume of H2SO4 used you can calculate C

C = n / V

V= 29.00 ml = 0.029 L

C= 2.425*10^-3 moles / 0.029 L

= 0.0836 mol/L