Question

How will you show that $H_{2}O_{2}$ will act like oxidizing agent in acidic as well as basic medium?

Answer 1

"Hydrogen peroxide" acts as "both" a "reducing agent" and an "oxidizing agent".

As an oxidizing agent, the oxygen of hydrogen peroxide (in -1 oxidation state) is reduced to ${ H }_{ 2 }O$ (-2 oxidation state).

For example, ${ H }_{ 2 }{ O }_{ 2 }\quad +\quad 2{ H }^{ + }\quad +\quad 2{ e }^{ - }\quad \rightarrow \quad 2{ H }_{ 2 }O$

When ${ H }_{ 2 }{ O }_{ 2 }$ (-1 oxidation state) as a "reducing agent", the oxygen of ${ H }_{ 2 }{ O }_{ 2 }$ is oxidized to ${ O }_{ 2 }$ ( 0 oxidation state) and "bubbles" are noticed.  

For example, $2Mn{ O }_{ 4 }^{ - }\quad +\quad 5{ H }_{ 2 }{ O }_{ 2 }\quad +\quad 6{ H }^{ + }\quad \rightarrow \quad 5{ O }_{ 2 }\quad +\quad 2{ Mn }^{ 2- }\quad +\quad 8{ H }_{ 2 }O$"

Answer 2

Answer:

Because the oxidation state of oxygen in H

2

O

2

is −1 which can be oxidized to

′

O

′

oxidation state by removing an e

−

or else can be reduced by adding an e

−

and oxidation state would be reduced to −2 oxidizing agent means oxidizing others itself getting reduced.

Acidic: H

2

O

2

+2H

+

+2e

−

→2H

2

O.

Basic: H

2

O

2

+2e

−

→2OH

−