The coloured spot of`KMnO_(4)` on any article can be bleached by

Options

A. `SO_(2)+H^(+)`
B. `C_(2)O_(4)^(2-)+H^(+)`
C. `H_(2)O_(2)+H^(+)`
D. all of these

Explanation

To solve the question regarding how the colored spot of KMnO₄ can be bleached, we need to understand the chemistry behind the bleaching process involving potassium permanganate (KMnO₄).

### Step-by-Step Solution:

1. **Understanding KMnO₄**:
- Potassium permanganate is a strong oxidizing agent and is known for its deep purple color due to the presence of MnO₄⁻ ions.

2. **Bleaching Process**:
- The term "bleaching" refers to the process of removing color from a substance. In the case of KMnO₄, it can be reduced to a colorless manganese ion (Mn²⁺) under acidic conditions.

3. **Reaction with Acid**:
- When KMnO₄ is treated with an acid (commonly sulfuric acid, H₂SO₄), the MnO₄⁻ ions are reduced to Mn²⁺ ions. The overall reaction can be represented as:
\[ 8 \text{H}^+ + \text{MnO}_4^- + 5 \text{e}^- \rightarrow \text{Mn}^{2+} + 4 \text{H}_2\text{O} \]
- This reaction shows that the purple color of KMnO₄ disappears as it is converted to the colorless Mn²⁺ ion.

4. **Conclusion**:
- Therefore, the colored spot of KMnO₄ on any article can be bleached by using an acid, which facilitates the reduction of MnO₄⁻ to Mn²⁺.

### Final Answer:
The colored spot of KMnO₄ can be bleached by using an acid (like sulfuric acid).