The reaction of one mol of bromine with ethyne yields

Options

A. `BrCH_2 - CH_2 Br`
B. `BrCH = CHBr`
C. `Br_2 CH - CH Br_2`
D. `CH_3 - CH_2 Br`

Explanation

To solve the question regarding the reaction of one mole of bromine with ethyne, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactants in this reaction are ethyne (C₂H₂) and bromine (Br₂).

2. **Understand the Reaction Type**:
- The reaction between ethyne and bromine is an example of electrophilic addition. In this case, bromine acts as an electrophile and adds across the triple bond of ethyne.

3. **Write the Chemical Equation**:
- The reaction can be represented as:
\[ C_2H_2 + Br_2 \rightarrow C_2H_2Br_2 \]
- Here, one mole of bromine reacts with one mole of ethyne to form 1,2-dibromoethane (C₂H₂Br₂).

4. **Determine the Product**:
- Since we are using one mole of bromine, the product formed will be 1,2-dibromoethane. If we had used two moles of bromine, we would have formed 1,1,2,2-tetrabromoethane, but since we are limited to one mole, we only get dibromination.

5. **Conclusion**:
- Therefore, the reaction of one mole of bromine with ethyne yields 1,2-dibromoethane.

### Final Answer:
The reaction of one mole of bromine with ethyne yields 1,2-dibromoethane (C₂H₂Br₂).

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