The strength of 11.2 volume solution of H₂O₂ is [Given that molar mass of H =1 g mol^-1 and O = 16 g mol^-1]

11.2 volume strength of H₂O₂ indicates that 11.2 L of oxygen gas is produced from 1 liter of H₂O₂ solution. Decomposition reaction of H₂O₂ is:

$2{\mathrm{H}}_2{\mathrm{O}}_2\to 2{\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2$

Above reaction states that 2 moles or 68 g of hydrogen peroxide forms 22.4 L of oxygen gas. Mass of hydrogen peroxide required for the formation of 11.2 L of oxygen gas is:

$\begin{array}{ccc}22.4 \mathrm{L} {\mathrm{O}}_2& =& 68 \mathrm{g} {\mathrm{H}}_2{\mathrm{O}}_2\\ 11.2 \mathrm{L} {\mathrm{O}}_2& =& 11.2 \mathrm{L} {\mathrm{O}}_2\times \frac{68 \mathrm{g} {\mathrm{H}}_2{\mathrm{O}}_2}{22.4 \mathrm{L} {\mathrm{O}}_2}\\ & =& 34 \mathrm{g} {\mathrm{H}}_2{\mathrm{O}}_2\end{array}$
Total volume of solution is 1 L and the strength of H₂O₂ is 34 g/L.

Strength of 11.2 volume solution of H₂O₂ is calculated as:

$\begin{array}{ccc}1000 \mathrm{mL} (\mathrm{or} 1 \mathrm{L})& =& 34 \mathrm{g} {\mathrm{H}}_2{\mathrm{O}}_2\\ 100 \mathrm{mL}& =& 100 \mathrm{mL}\times \frac{34 \mathrm{g} {\mathrm{H}}_2{\mathrm{O}}_2}{1000 \mathrm{mL}}\\ & =& 3.4\%\end{array}$