Hydrogen peroxide reacts with iodine in basic medium to give:

Select the correct statement.

Which metal oxide among the following gives $H_2O_2$ on treatment with dilute acid?

When $CO_2$ is bubbled through a solution of barium peroxide in water:

$I. \, H_2O_2 + O_3 \rightarrow H_2O + 2O_2$
$II. \, H_2O_2 + Ag_2O \rightarrow 2Ag + H_2O + O_2$
The role of hydrogen peroxide in the above reactions is respectively:

The normality of $20$ volume solution of hydrogen peroxide is (in $N$)