Moderate acts as a bleaching agent only in presence of

Options

A. Silica
B. Graphite
C. Diamond
D. Carborundum

Explanation

To solve the question regarding the conditions under which moderate acts as a bleaching agent, we need to analyze the properties of moderate and the factors that influence its bleaching action.

### Step-by-Step Solution:

1. **Understanding Bleaching Agents**:
- A bleaching agent is a substance that removes color from materials, typically by oxidation or reduction. Common bleaching agents include chlorine, hydrogen peroxide, and sodium hypochlorite.

2. **Identifying Moderate**:
- The term "moderate" in this context likely refers to a specific chemical compound. For example, it could refer to a moderate concentration of hydrogen peroxide or another bleaching agent.

3. **Presence of Catalysts or Activators**:
- Many bleaching agents require certain conditions or additional substances to enhance their bleaching action. For example, hydrogen peroxide acts more effectively in the presence of catalysts like acids or certain metal ions.

4. **Conclusion**:
- Moderate acts as a bleaching agent primarily in the presence of an activator or a catalyst. For example, it may require an acidic medium or a specific metal ion to enhance its bleaching properties.

### Final Answer:
Moderate acts as a bleaching agent only in the presence of an activator or catalyst, such as an acid or a metal ion.

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