Question

$A)$ Give a method for the manufacture of hydrogen peroxide and explain the reactions involved therein.

$B)$ Illustrate oxidising, reducing and acidic properties of hydrogen peroxide with equations.

Answer 1

$A)$ Production of hydrogen peroxide

Hydrogen peroxide can be prepared by acidification of barium peroxide in presence of $H_{2}S{O}_4.$

The excess water molecules then produced are evaporated under reduced pressure.

The reaction is as follows:

$Ba{O}_2.8H_{2}O\left(s\right)+H_{2}S{O}_4\left(aq\right)\to BaS{O}_4\left(s\right)+H_2{O}_2\left(aq\right)+8H_{2}O\left(l\right)$

$B)$

$\left(i\right)$ $H_2{O}_2$ acting as oxidising agent

$H_2{O}_2+2HI\to I_2+2H_{2}O$

$H=+1$ $H=+1$ $I=0$ $H=+1$

$O=-1$ $I=-1$ $O=-2$

Therefore,



In the given reaction, $H_2{O}_2$ is oxidising $HI$ to $I_2$ and itself getting reduced to $H_{2}O.$

Thus, here $H_2{O}_2$ is acting as an oxidising agent.

$\left(ii\right)$ $H_2{O}_2$ acting as reducing agent

$HOCl+H_2{O}_2\to H_3{O}^{+}+C{l}^{-}+O_2$

$H=+1$ $H=+1$ $H=+1$ $Cl=-1$ $O=0$

$O=-2$ $O=-1$ $O=-2$

$Cl=+1$

Therefore,



In the given reaction, $H_2{O}_2$ is reducing $HOCl$ to $C{l}^{-}$ and itself getting oxidised to $O_2$

Thus, in reaction $B,H_2{O}_2$ is acting as a reducing agent.

$\left(iii\right)$ Acidic property of Hydrogen peroxide

It turns blue litmus red but its dilute solution is almost neutral to litmus which signifies that it is a weak acid.

Its acidic nature can be further supported by its reaction with $NaOH$ (base).

$2NaOH+H_2{O}_2\to N{a}_2{O}_2+2H_{2}O$