$1 \ mL$ of "$x$ volume" $H_2O_2$ solution on heating gives $20 \ mL$ of oxygen gas at $STP$. The $(w/v) \%$ corresponding to "$x$ volume" of $H_2O_2$ is

The last drop of water can be removed from $H_2O_2$ by :-

The $pH$ of a solution of $H_2O_2$ is $6.0$. Some chlorine gas is bubbled into this solution. Which of the following is correct?

In which of the following reactions does $H_2O_2$ act as a reducing agent?
$(I)$ $H_2O_2 + 2H^{+} + 2e^- \to 2H_2O$
$(II)$ $H_2O_2 \to O_2 + 2H^{+} + 2e^-$
$(III)$ $H_2O_2 + 2e^- \to 2OH^{-}$
$(IV)$ $H_2O_2 + 2OH^{-} \to O_2 + 2H_2O + 2e^-$

Electrolysis of $X$ gives $Y$ at anode. Vacuum distillation of $Y$ gives $H_2O_2$. The number of peroxy $(O-O)$ bonds present in $X$ and $Y$ respectively are :

The environmentally friendly chemical used nowadays for bleaching paper in the presence of a suitable catalyst is