An acidic solution of hydrogen peroxide behaves as an oxidising as well as reducing agent. Illustrate it with the help of a chemical equation.

Explanation

To illustrate how an acidic solution of hydrogen peroxide (H2O2) behaves as both an oxidizing agent and a reducing agent, we can analyze two different chemical reactions.

### Step 1: Understanding Oxidizing and Reducing Agents
- **Oxidizing Agent**: A substance that oxidizes another substance by accepting electrons, and itself gets reduced.
- **Reducing Agent**: A substance that reduces another substance by donating electrons, and itself gets oxidized.

### Step 2: Hydrogen Peroxide as an Oxidizing Agent
In an acidic solution, hydrogen peroxide can oxidize potassium iodide (KI) to iodine (I2).

**Chemical Equation**:
\[ \text{H}_2\text{O}_2 + 2 \text{KI} + 2 \text{H}_2\text{SO}_4 \rightarrow \text{I}_2 + 2 \text{K}_2\text{SO}_4 + 2 \text{H}_2\text{O} \]

**Oxidation States**:
- In potassium iodide, iodine (I) has an oxidation state of -1.
- In iodine (I2), the oxidation state is 0.
- The change from -1 to 0 indicates that iodine is losing electrons, which means it is being oxidized.

### Step 3: Hydrogen Peroxide as a Reducing Agent
In another reaction, hydrogen peroxide can reduce potassium permanganate (KMnO4) to manganese dioxide (MnO2) in acidic medium.

**Chemical Equation**:
\[ \text{KMnO}_4 + \text{H}_2\text{O}_2 + 2 \text{H}_2\text{SO}_4 \rightarrow \text{MnO}_2 + \text{K}_2\text{SO}_4 + 2 \text{H}_2\text{O} + \text{O}_2 \]

**Oxidation States**:
- In KMnO4, manganese (Mn) has an oxidation state of +7.
- In MnO2, manganese has an oxidation state of +4.
- The change from +7 to +4 indicates that manganese is gaining electrons, which means it is being reduced.

### Conclusion
In summary, hydrogen peroxide acts as an oxidizing agent when it oxidizes potassium iodide to iodine, and it acts as a reducing agent when it reduces potassium permanganate to manganese dioxide.