How many ‘mL’ of perhydrol is required to produce sufficient oxygen which can be used to completely convert 2L of $S{O}_2$ gas to $S{O}_3$ gas

Perhydrol means 30% solution of $H_2{O}_2.$ $H_2{O}_2$ decomposes as

$2H_2{O}_2\to 2H_{2}O+O{}_2$ volume strength of $30\%H_2{O}_2$ solution is 100 that means 1 mL of this solution on decomposition gives 100mL oxygen.

$\begin{array}{c}S{O}_2+\frac{1}{2}{O}_2\to S{O}_3\\ 1L\frac{1}{2}L1L\\ 2L1L2L\end{array}$

Since, 100 mL of oxygen is obtained by $=1mLof{H}_2{O}_2$

$\therefore 1000mL$ of oxygen will be obtained by $=\frac{1}{100}\times 1000mLof{H}_2{O}_2$

                                                                            $\text{=10}\text{mL}\text{of}{\text{H}}_2{O}_2$