Which isomer of xylene can give three different monochloroderivatives ?

Options

A. o-xylene
B. m-xylene
C. p-xylene
D. xylene cannot give a monochioro derivative

Answer

To determine which isomer of xylene can give three different monochloroderivatives, we will analyze the three isomers of xylene: ortho-xylene, meta-xylene, and para-xylene.

### Step 1: Understand the structure of xylene isomers
Xylene has three isomers:
1. **Ortho-xylene (o-xylene)**: Two methyl groups on adjacent carbons (1,2-dimethylbenzene).
2. **Meta-xylene (m-xylene)**: Two methyl groups separated by one carbon (1,3-dimethylbenzene).
3. **Para-xylene (p-xylene)**: Two methyl groups on opposite sides (1,4-dimethylbenzene).

### Step 2: Analyze ortho-xylene
- **Structure**:
- Methyl groups on carbons 1 and 2.
- **Chlorination**:
- Chlorine can be substituted on:
- Carbon 3 (ortho to one methyl, meta to the other)
- Carbon 4 (para to one methyl, meta to the other)
- Carbon 5 (meta to one methyl, ortho to the other)
- Carbon 6 (ortho to one methyl, para to the other)
- **Derivatives**:
- The chlorination at carbons 3 and 5 gives the same product, as does chlorination at carbons 4 and 6.
- **Total unique products**: 2.

### Step 3: Analyze meta-xylene
- **Structure**:
- Methyl groups on carbons 1 and 3.
- **Chlorination**:
- Chlorine can be substituted on:
- Carbon 2 (ortho to one methyl, ortho to the other)
- Carbon 4 (para to one methyl, meta to the other)
- Carbon 5 (meta to both methyl groups)
- Carbon 6 (ortho to one methyl, para to the other)
- **Derivatives**:
- The chlorination at carbons 2 and 6 gives the same product, as does chlorination at carbons 4 and 5.
- **Total unique products**: 3.

### Step 4: Analyze para-xylene
- **Structure**:
- Methyl groups on carbons 1 and 4.
- **Chlorination**:
- Chlorine can be substituted on:
- Carbon 2 (ortho to one methyl, meta to the other)
- Carbon 3 (meta to both methyl groups)
- Carbon 5 (meta to one methyl, ortho to the other)
- Carbon 6 (ortho to one methyl, para to the other)
- **Derivatives**:
- The chlorination at carbons 2 and 6 gives the same product, as does chlorination at carbons 3 and 5.
- **Total unique products**: 1.

### Conclusion
The isomer of xylene that can give three different monochloroderivatives is **meta-xylene**.