A chemical A is used for the preparation of washing soda to recover ammonia. When `CO_(2)` is bubbled through an aqueous solution of A, the solution turns milky. It is used in white washing due to disinfectant nature what is the chemical formula of A?

Options

A. `Ca(HCO_(3))_(2)`
B. `CaO`
C. `Ca(OH)_(2)`
D. `CaCO_(3)`

Explanation

To find the chemical A based on the clues provided in the question, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Characteristics of Chemical A**:
- The chemical A is used for the preparation of washing soda to recover ammonia.
- When CO₂ is bubbled through an aqueous solution of A, the solution turns milky.
- It is used in whitewashing due to its disinfectant nature.

2. **Determine the Reaction Involved**:
- The milky solution indicates the formation of calcium carbonate (CaCO₃). This is a common observation when carbon dioxide is bubbled through a solution containing calcium ions.
- The reaction can be represented as:
\[ \text{Ca(OH)}_2 (aq) + \text{CO}_2 (g) \rightarrow \text{CaCO}_3 (s) + \text{H}_2O (l) \]
- Here, calcium hydroxide reacts with carbon dioxide to produce calcium carbonate, which is the milky substance.

3. **Identify Chemical A**:
- Since calcium carbonate is formed from the reaction of calcium hydroxide with carbon dioxide, we can deduce that chemical A must be calcium hydroxide (Ca(OH)₂).
- Calcium hydroxide is also known for its use in whitewashing and has disinfectant properties.

4. **Conclusion**:
- Therefore, the chemical formula of A is:
\[ \text{Ca(OH)}_2 \]

### Final Answer:
The chemical formula of A is **Ca(OH)₂** (calcium hydroxide).