Which can be used as monomer in a polymerization reaction?

Options

A. `C_2H_3Cl`
B. `C_2H_4`
C. `C_2H_5Cl`
D. `C_2H_3COOH`

Answer

To determine which of the given compounds can be used as a monomer in a polymerization reaction, we need to analyze each option and see if they can undergo polymerization to form a polymer.

### Step-by-Step Solution:

1. **Understanding Monomers and Polymers**:
- A monomer is a small molecule that can join together with other monomers to form a polymer.
- Polymerization is the process where monomers chemically bond to form a larger, high molecular weight compound known as a polymer.

2. **Analyzing Each Compound**:
- **Option 1: C2H3Cl (Vinyl Chloride)**:
- Structure: C=C with one carbon having two hydrogens and the other having one chlorine and one hydrogen.
- This compound can undergo polymerization to form polyvinyl chloride (PVC), which is a well-known polymer.
- **Conclusion**: C2H3Cl can be used as a monomer.

- **Option 2: C2H4 (Ethene)**:
- Structure: C=C with each carbon having two hydrogens.
- Ethene can polymerize to form polyethene (or polyethylene), a common plastic.
- **Conclusion**: C2H4 can be used as a monomer.

- **Option 3: C2H5Cl (Ethyl Chloride)**:
- Structure: CH3-CH2-Cl.
- Ethyl chloride does not have a double bond and cannot undergo polymerization to form a polymer.
- **Conclusion**: C2H5Cl cannot be used as a monomer.

- **Option 4: C2H3COOH (Acrylic Acid)**:
- Structure: CH2=CH-COOH.
- Acrylic acid can polymerize to form polyacrylic acid, which is used in various applications.
- **Conclusion**: C2H3COOH can be used as a monomer.

3. **Final Conclusion**:
- The compounds that can be used as monomers in a polymerization reaction are:
- C2H3Cl (Vinyl Chloride)
- C2H4 (Ethene)
- C2H3COOH (Acrylic Acid)
- Therefore, the correct options are 1, 2, and 4.

### Summary of Monomers:
- **C2H3Cl**: Yes, can polymerize (PVC).
- **C2H4**: Yes, can polymerize (Polyethylene).
- **C2H5Cl**: No, cannot polymerize.
- **C2H3COOH**: Yes, can polymerize (Polyacrylic Acid).