The strength of 11.2 volume solution of H _ 2 O _ 2 is [Given that,...

Molarity of ${H}_{2}O = \dfrac{Volumestrength}{11 .2}$

$M = \dfrac{11.2}{11.2} = 1$

$∴$ $1$ molar means $1000mL$ solution contains $1mol{H}_{2}{O}_{2} = 1 \times 34g$

Since, the strength is represented as weight of the solute in $1L$ of the solution. The strength of the solution will be $34g{L}^{- 1}$.

Note: The question should've mentioned that we need to find the mass by volume percentage.

Percentage w/v $= \dfrac{34}{1000} \times 100 = 3.4$