Volume strength of 1M solution of ${\mathrm{H}}_2{\mathrm{O}}_2$ is: 

The volume strength of 1M solution of ${\mathrm{H}}_2{\mathrm{O}}_2$  is 11.2 as the balanced reaction is as follows:

$2{\mathrm{H}}_2\underset{-1 }{{\mathrm{O}}_2} \to 2{\mathrm{H}}_2\underset{-2}{\mathrm{O} }+ \underset{0}{{\mathrm{O}}_2 }$  (oxidation state of O)

So, 2 moles of ${\mathrm{H}}_2{\mathrm{O}}_2$ gives  1 mole of O₂

Therefore, 1 mole of ${\mathrm{H}}_2{\mathrm{O}}_2$ will give 11.2 L of ${\mathrm{O}}_2$ gas.

Volume strength=11.2L $\times$ molarity.

Hence, for 1M ${\mathrm{H}}_2{\mathrm{O}}_2$ volume strength is 11.2