Nitration of xylene gives only one mono-nitro derivaties. Which xylene is it?

Options

A. orhto
B. meta
C. para
D. Both `o` and `p`

Explanation

To determine which xylene gives only one mono-nitro derivative upon nitration, we need to analyze the structure of the different isomers of xylene: ortho-xylene, meta-xylene, and para-xylene.

### Step-by-Step Solution:

1. **Identify the Isomers of Xylene**:
- Xylene has three isomers: ortho-xylene (1,2-dimethylbenzene), meta-xylene (1,3-dimethylbenzene), and para-xylene (1,4-dimethylbenzene).

2. **Understand the Nitration Reaction**:
- Nitration typically involves the introduction of a nitro group (NO2) into an aromatic compound using a mixture of concentrated sulfuric acid (H2SO4) and nitric acid (HNO3).

3. **Analyze Ortho-Xylene**:
- Ortho-xylene has two methyl groups on adjacent carbon atoms. When nitrated, it can yield two different mono-nitro derivatives because the nitro group can attach to either of the two positions relative to the methyl groups.

4. **Analyze Meta-Xylene**:
- Meta-xylene has two methyl groups separated by one carbon atom. Nitration of meta-xylene can produce three different mono-nitro derivatives due to the different positions where the nitro group can be attached.

5. **Analyze Para-Xylene**:
- Para-xylene has two methyl groups on opposite sides of the benzene ring. When nitrated, it can only yield one mono-nitro derivative because the nitro group can only attach to one specific position relative to the two methyl groups.

6. **Conclusion**:
- Since only para-xylene yields a single mono-nitro derivative upon nitration, the answer to the question is para-xylene.

### Final Answer:
The xylene that gives only one mono-nitro derivative upon nitration is **para-xylene**.

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