Which of the following would be produced when acetylene reacts with excess `Cl_(2)`?

Options

A. `CH_(3) CH_(2)Cl`
B. Westron
C. `CHCl = CHCl`
D. Westrosol

Answer

To determine the product formed when acetylene reacts with excess chlorine (Cl₂), we can follow these steps:

### Step 1: Identify the Reactants
Acetylene is a simple alkyne with the formula C₂H₂, which has a triple bond between the two carbon atoms. The structure can be represented as:
```
H-C≡C-H
```

### Step 2: Understand the Reaction Type
The reaction between acetylene and chlorine is an addition reaction. In this case, the chlorine molecules will add across the triple bond of the acetylene.

### Step 3: First Addition of Chlorine
When acetylene reacts with one molecule of Cl₂, the triple bond will break, and one chlorine atom will attach to each carbon atom. This results in the formation of 1,2-dichloroethene:
```
H-C(Cl)-C(Cl)-H
```
This compound is known as 1,2-dichloroethene.

### Step 4: Second Addition of Chlorine
Since the problem states that there is excess Cl₂, the reaction will continue. The remaining double bond in 1,2-dichloroethene will react with another Cl₂ molecule. Each carbon will again bond with another chlorine atom, resulting in the formation of 1,1,2,2-tetrachloroethane:
```
Cl-C(Cl)-C(Cl)-Cl
```
This compound is commonly referred to as Westron.

### Step 5: Conclusion
The final product of the reaction between acetylene and excess chlorine is 1,1,2,2-tetrachloroethane (Westron).

### Final Answer
The product formed when acetylene reacts with excess Cl₂ is **1,1,2,2-tetrachloroethane**.

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