Problem

The concentration of hydrogen peroxide,

\text{H}_2\text{O}_2

, in excess aqueous sulfuric acid,

\text{H}_2\text{SO}_4

, can be determined by redox titration using potassium permanganate,

\text{KMnO}_4

as follows:

2\text{KMnO}_4(\text{aq}) + 5\text{H}_2\text{O}_2(\text{l}) + 3\text{H}_2\text{SO}_4 \rightarrow 2\text{MnSO}_4(\text{aq}) + \text{K}_2\text{SO}_4(\text{aq}) + 8\text{H}_2\text{O}(\text{l}) + 5\text{O}_2(\text{g})

10.00 \text{ cm}^3

sample of

\text{H}_2\text{O}_2

solution requires

18.00 \text{ cm}^3

of a

0.0500 \text{ mol dm}^{-3}

solution of

\text{KMnO}_4

to reach the equivalence point in a titration. Calculate the concentration of

\text{H}_2\text{O}_2

in the solution.