Which of the following is not used as a bleaching agent in the presence of moisture?

Give the reaction of $I_2$ with $H_2O_2$ in the presence of a basic medium.

The volume concentration of hydrogen peroxide having $6.8 \%$ concentration will be

Consider the following reaction:
$2 HSO_{4}^{-}(aq)$ $\xrightarrow[\text{(2) Hydrolysis}]{\text{(1) Electrolysis}} H_{2}S_{2}O_{8}(aq)$ $\xrightarrow{\text{Hydrolysis}} 2 HSO_{4}^{-}(aq) + 2 H^{+}(aq) + A(aq)$
The dihedral angle in product $A$ in its solid phase at $110 \ K$ is ....$^{\circ}$

$A$ compound $(MO_2)$ of a group $1$ element $(M)$ is hydrolyzed to form $M^{+}$,$OH^{-}$,$X$,and $Y$. When $X$ reacts with $I_2$ in a basic medium,the products formed are $I^{-}$,water,and $Y$. Then $X$ and $Y$ are respectively:

The covalent radius of oxygen is measured in: