Assertion:A solution of bromine in `C Cl_4` is decolorised on passing acetylene gas through it
Reasoning : Bromine is expelled from the solution by acetylene gas

Options

A. Assertion is true but the Reason is false
B. Assertion is false, Reason is true
C. Both Assertion and Reason are true and the Reason is a correct explanation of the Reason.
D. Both Assertion and Reason are true but Reason is not a correct explanation of the assertion.

Explanation

To solve the question, we need to analyze both the assertion and the reasoning provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that a solution of bromine in carbon tetrachloride (CCl4) is decolorized when acetylene gas (C2H2) is passed through it.
- Bromine (Br2) is a reddish-brown liquid, and when it reacts with unsaturated compounds (like acetylene), it undergoes an addition reaction, which leads to the loss of color (decolorization).

2. **Chemical Reaction**:
- When acetylene (C2H2) is introduced to bromine in CCl4, the acetylene reacts with bromine to form dibromoethane (C2H2Br2).
- The reaction can be represented as:
\[ C2H2 + Br2 \rightarrow C2H2Br2 \]
- This reaction indicates that the bromine is being consumed in the reaction, leading to the decolorization of the bromine solution.

3. **Conclusion on Assertion**:
- Since the bromine solution is indeed decolorized due to the reaction with acetylene, the assertion is **true**.

4. **Understanding the Reasoning**:
- The reasoning states that "bromine is expelled from the solution by acetylene gas."
- However, this statement is misleading. Bromine is not expelled; instead, it is consumed in the reaction with acetylene.

5. **Conclusion on Reasoning**:
- Therefore, the reasoning is **false** because it incorrectly describes the process as expulsion rather than consumption.

6. **Final Answer**:
- The correct conclusion is that the assertion is true, but the reasoning is false. Thus, the answer is: Assertion is true, Reason is false.