Which substance does not speed up the decomposition of $H_2O_2$?

The species that is not hydrolysed in water is

Three vessels $(A, B, C)$ contain $H_2O_2$ solution. In vessel $A$,$500 \ mL$ of $10 \ vol \ H_2O_2$ is present. $100 \ mL$ of $30 \ vol \ H_2O_2$ is present in vessel $B$. Vessel $C$ is filled with $250 \ mL$ of $2 \ M \ H_2O_2$. The weight (in $g$) of $H_2O_2$ present in these vessels follows the order:

$A$ commercial sample of hydrogen peroxide is labeled as $10$ volume. Its percentage concentration is approximately ............... $\%$.

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?

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