Question

A 25.00 mL sample of an H2SO4 solution of unknown concentration is titrated with a 0.1322 M KOH solution. A volume of 41.22 mL of KOH is required to reach the equivalence point. What is the concentration of the unknown H2SO4 solution? Express your answer in molarity to four significant figures.

Answer 1

Answer:

$0.1090\ \text{M}$

Explanation:

Volume of $KOH$ = 41.22 mL

Molarity of $KOH$ = 0.1322 M

Number of moles of $KOH$

$n=\text{Molarity}\times \text{Volume of }KOH\\\Rightarrow n=0.1322\times 41.22\times 10^{-3}\\\Rightarrow n=0.005449284\ \text{mol}$

2 moles of $KOH$ reacts with 1 mole of $H_2SO_4$

So,

$0.005449284\ \text{mol}$ of $KOH$ reacts with M mole of $H_2SO_4$

$M=\dfrac{0.005449284}{2}=0.002724642\ \text{mol}$

Volume of $H_2SO_4=25\times 10^{-3}\ \text{L}$

Concentration of $H_2SO_4$ is

$M=\dfrac{0.002724642}{25\times 10^{-3}}\\\Rightarrow M=0.10898568\approx 0.1090\ \text{M}$

The concentration of the unknown $H_2SO_4$ solution is $0.1090\ \text{M}$.