Write chemical reactions to justify that hydrogen peroxide can function as an oxidizing as well as a reducing agent.

Hydrogen peroxide,$H_{2}O_{2}$,acts as an oxidizing as well as a reducing agent in both acidic and alkaline media.
Reactions involving oxidizing actions (where $H_{2}O_{2}$ is reduced to $H_{2}O$ or $OH^{-}$):
$1) \ 2Fe^{2+} + 2H^{+} + H_{2}O_{2} \longrightarrow 2Fe^{3+} + 2H_{2}O$
$2) \ PbS + 4H_{2}O_{2} \longrightarrow PbSO_{4} + 4H_{2}O$
Reactions involving reducing actions (where $H_{2}O_{2}$ is oxidized to $O_{2}$):
$1) \ 2MnO_{4}^{-} + 6H^{+} + 5H_{2}O_{2} \longrightarrow 2Mn^{2+} + 8H_{2}O + 5O_{2}$
$2) \ I_{2} + H_{2}O_{2} + 2OH^{-} \longrightarrow 2I^{-} + 2H_{2}O + O_{2}$