Drinking water can be made bacteria free by

Options

A. `CaOCl_(2)`
B. `CaCl_(2)`
C. `CuCl_(2)`
D. `CaCO_(3)`

Answer

### Step-by-Step Solution:

1. **Understanding the Problem**: The question asks how to make drinking water bacteria-free. This involves identifying a chemical compound that can effectively disinfect water.

2. **Identifying the Chemical**: One of the most common chemicals used for disinfecting drinking water is calcium hypochlorite. Its chemical formula is Ca(OCl)₂.

3. **Function of Calcium Hypochlorite**: Calcium hypochlorite is known for its ability to kill bacteria and other pathogens in water. It releases chlorine when dissolved in water, which is a powerful disinfectant.

4. **Comparison with Other Chemicals**: While chlorine gas and sodium hypochlorite are also used for water treatment, calcium hypochlorite is more stable and has a longer shelf life compared to chlorine gas. This makes it a preferred choice for water purification.

5. **Application**: Calcium hypochlorite is used not only in drinking water treatment but also in swimming pools and other sanitation processes due to its effectiveness in killing bacteria.

6. **Conclusion**: The correct answer to the question is calcium hypochlorite (Ca(OCl)₂), which is used to make drinking water bacteria-free.

### Final Answer:
Drinking water can be made bacteria-free by using calcium hypochlorite (Ca(OCl)₂).

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