Slaked lime on exposure to air gives

Options

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

Answer

To solve the question regarding what slaked lime gives upon exposure to air, we can break down the process step by step.

### Step-by-Step Solution:

1. **Identify Slaked Lime**:
- Slaked lime is chemically known as calcium hydroxide, with the formula \( \text{Ca(OH)}_2 \).

2. **Exposure to Air**:
- When slaked lime is exposed to air, it primarily reacts with carbon dioxide (\( \text{CO}_2 \)) present in the atmosphere.

3. **Chemical Reaction**:
- The reaction between calcium hydroxide and carbon dioxide can be represented as:
\[ \text{Ca(OH)}_2 + \text{CO}_2 \rightarrow \text{CaCO}_3 + \text{H}_2\text{O} \]
- In this reaction, calcium carbonate (\( \text{CaCO}_3 \)) is formed along with water.

4. **Properties of Calcium Carbonate**:
- Calcium carbonate is known to make water appear milky when it is formed, which is a characteristic property of this compound.

5. **Conclusion**:
- Therefore, upon exposure to air, slaked lime primarily gives calcium carbonate (\( \text{CaCO}_3 \)), which is also known as calcium carbonate.

### Final Answer:
Slaked lime on exposure to air gives calcium carbonate (\( \text{CaCO}_3 \)).

---