JEE Main 2022 — Hydrogen Question with Solution

It acts as an oxidising as well as reducing agent in both acidic and alkaline media. Simple reactions are described below.

(i) Oxidising action in acidic medium

$2{\mathrm{Fe}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+{\mathrm{H}}_2{\mathrm{O}}_2\left(\mathrm{aq}\right)\to 2{\mathrm{Fe}}^{3+}\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

(ii) Reducing action in acidic medium

$2{\mathrm{MnO}}_4^{-}+6{\mathrm{H}}^{+}+5{\mathrm{H}}_2{\mathrm{O}}_2\to 2{\mathrm{Mn}}^{2+}+8{\mathrm{H}}_2\mathrm{O}+5{\mathrm{O}}_2$

(iii) Oxidising action in basic medium

$2{\mathrm{Fe}}^{2+}+{\mathrm{H}}_2{\mathrm{O}}_2\to 2{\mathrm{Fe}}^{3+}+2{\mathrm{OH}}^{-}$

(iv) Reducing action in basic medium

${\mathrm{I}}_2+{\mathrm{H}}_2{\mathrm{O}}_2+2{\mathrm{OH}}^{-}\to 2{\mathrm{I}}^{-}+2{\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2$

The density of hydrogen peroxide is more than that of heavy water

Density of ${\mathrm{D}}_2\mathrm{O}=1.1 \mathrm{g}/\mathrm{cc}$

Density of ${\mathrm{H}}_2{\mathrm{O}}_2=1.45 \mathrm{g}/\mathrm{cc}$