Assertion: `CaCO_(3)` is prepared by passing carbon dioxide gas through slaked lime.
Reason: Passingg excess of `CO_(2)` through slaked lime leads to the formation off quick lime.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To solve the assertion-reason question, we will analyze both the assertion and the reason step by step.

### Step 1: Understand the Assertion
The assertion states that calcium carbonate (CaCO₃) is prepared by passing carbon dioxide (CO₂) gas through slaked lime.

- **Slaked lime** is chemically represented as calcium hydroxide (Ca(OH)₂).
- The reaction can be represented as:
\[ \text{Ca(OH)}_2 + \text{CO}_2 \rightarrow \text{CaCO}_3 + \text{H}_2\text{O} \]
- This indicates that when CO₂ is passed through slaked lime, calcium carbonate is indeed formed.

### Step 2: Understand the Reason
The reason states that passing excess CO₂ through slaked lime leads to the formation of quick lime.

- Quick lime is chemically known as calcium oxide (CaO).
- However, when excess CO₂ is passed through slaked lime (Ca(OH)₂), the reaction that occurs is:
\[ \text{Ca(OH)}_2 + 2\text{CO}_2 \rightarrow \text{Ca(HCO}_3)_2 \]
- This results in the formation of calcium bicarbonate (Ca(HCO₃)₂), not quick lime. Therefore, the reason provided is incorrect.

### Conclusion
- The assertion is **true** because calcium carbonate is formed when CO₂ is passed through slaked lime.
- The reason is **false** because excess CO₂ does not lead to the formation of quick lime; it leads to the formation of calcium bicarbonate.

### Final Answer
The correct option is that the assertion is true and the reason is false.

---