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

Assertion $(A)$: The colour of old lead paintings can be restored by washing them with a dilute solution of $H_2O_2$.
Reason $(R)$: Hydrogen peroxide reduces $PbS$ to $Pb$.

$H_2O_2$ reacts as a reducing agent with:
$(I)$ $KMnO_4$
$(II)$ $K_2Cr_2O_7$
$(III)$ $Ag_2O$
$(IV)$ $HNO_3$

Which of the following statements is correct?

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:

The volume strength (in $L$) of $3$ $N$ $H_2O_2$ is approximately