In the reaction `2Br^(-) + X_2 to Br_2 + 2X^(-) ,X_2` is 

Options

A. `Cl_2`
B. `Br_2`
C. `I_2`
D. `N_2`

Answer

To solve the question, we need to identify the element \(X_2\) in the reaction:

\[ 2 \text{Br}^- + X_2 \rightarrow \text{Br}_2 + 2 \text{X}^- \]

### Step-by-Step Solution:

1. **Understand the Reaction**:
The reaction involves bromide ions (\( \text{Br}^- \)) being oxidized to bromine (\( \text{Br}_2 \)). This means that \(X_2\) must be a substance that can oxidize bromide ions.

2. **Identify the Oxidizing Agent**:
An oxidizing agent is a substance that gains electrons in a chemical reaction. In this case, \(X_2\) must be able to accept electrons from \( \text{Br}^- \) to form \( \text{Br}_2 \).

3. **Evaluate the Options**:
The options provided are \( \text{I}_2 \), \( \text{Cl}_2 \), and \( \text{N}_2 \). We need to determine which of these can act as an oxidizing agent for bromide ions.

- **\( \text{I}_2 \)**: Iodine is a weaker oxidizing agent compared to bromine. It is unlikely to oxidize bromide ions to bromine.
- **\( \text{Cl}_2 \)**: Chlorine is a strong oxidizing agent and can oxidize bromide ions to bromine.
- **\( \text{N}_2 \)**: Nitrogen does not act as an oxidizing agent in this context.

4. **Conclusion**:
Since \( \text{Cl}_2 \) can oxidize \( \text{Br}^- \) to \( \text{Br}_2 \), the correct answer for \(X_2\) in the reaction is \( \text{Cl}_2\).

### Final Answer:
Thus, \(X_2\) is \( \text{Cl}_2 \).

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