Which one of the following monomers gives the polymer neoprene on polymerization?

Options

A. `CH_(2)=CH-Cl`
B. `Cl_(2)C="CC"l_(2)`
C. `F_(2)C=CF_(2)`
D. `CH_(2)=underset(Cl)underset(|)C-CH=CH_(2)`

Answer

To determine which monomer gives the polymer neoprene upon polymerization, we can follow these steps:

### Step-by-Step Solution:

1. **Identify Neoprene**:
Neoprene is a type of synthetic rubber. It is important to know that neoprene is produced through the polymerization of a specific monomer.

2. **Determine the Monomer**:
The monomer that polymerizes to form neoprene is known as chloroprene. The chemical formula for chloroprene is C4H5Cl, and its IUPAC name is 2-chloro-1,3-butadiene.

3. **Structure of Chloroprene**:
The structure of chloroprene can be represented as:
\[ \text{CH}_2= \text{C}(\text{Cl})-\text{CH}=\text{CH}_2 \]
This shows that chloroprene has a double bond between the carbon atoms, which is essential for the polymerization process.

4. **Polymerization Process**:
During polymerization, chloroprene undergoes a reaction where the double bonds open up and link together to form long chains. The reaction can be represented as:
\[ n \, \text{(CH}_2=\text{C}(\text{Cl})-\text{CH}=\text{CH}_2) \rightarrow \text{(C}_4\text{H}_5\text{Cl})_n \]
This results in the formation of the polymer neoprene.

5. **Conclusion**:
Based on the above information, the correct answer to the question is that the monomer which gives neoprene on polymerization is chloroprene.

### Final Answer:
The monomer that gives the polymer neoprene on polymerization is **chloroprene (2-chloro-1,3-butadiene)**.

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