Write the chemical formula for bleaching powder .How is bleaching powder prepared ? For what purpose is it used in paper factories ?

Explanation

### Step-by-Step Solution:

1. **Chemical Formula for Bleaching Powder**:
- The chemical formula for bleaching powder is **Ca(OCl)₂** or **CaCl₂·O**. It is also known as calcium oxychloride.

2. **Preparation of Bleaching Powder**:
- Bleaching powder is prepared by passing chlorine gas (Cl₂) over dry slaked lime (calcium hydroxide, Ca(OH)₂). The reaction can be summarized as follows:
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