Which of the following isomer having molecular formula `C_(6)H_(14)` will give minimum number of mono-chloro derivatives?

Options

A. Hexane
B. 2-Methylpentane
C. 3-Methylpentane
D. 2, 3-Dimethyl butane

Answer

To determine which isomer of the molecular formula C₆H₁₄ gives the minimum number of monochloro derivatives, we need to analyze the different isomers of C₆H₁₄ and count the number of distinct carbon environments present in each isomer. The number of distinct carbon environments will dictate how many unique monochloro derivatives can be formed upon chlorination.

### Step-by-Step Solution:

1. **Identify the Isomers of C₆H₁₄:**
The molecular formula C₆H₁₄ corresponds to several structural isomers. The common isomers include:
- n-Hexane (straight-chain)
- 2-Methylpentane
- 3-Methylpentane
- 2,2-Dimethylbutane
- 2,3-Dimethylbutane
- 3,3-Dimethylbutane

2. **Analyze n-Hexane:**
- Structure: CH₃-CH₂-CH₂-CH₂-CH₂-CH₃
- Carbon environments: All carbons in n-hexane are either primary (CH₃) or secondary (CH₂).
- Types of carbon: 2 (1 primary and 1 secondary).
- Number of monochloro derivatives = 2.

3. **Analyze 2-Methylpentane:**
- Structure: CH₃-CH(CH₃)-CH₂-CH₂-CH₃
- Carbon environments: 3 types (1 primary, 1 secondary, and 1 tertiary).
- Number of monochloro derivatives = 3.

4. **Analyze 3-Methylpentane:**
- Structure: CH₃-CH₂-CH(CH₃)-CH₂-CH₃
- Carbon environments: 3 types (1 primary, 1 secondary, and 1 tertiary).
- Number of monochloro derivatives = 3.

5. **Analyze 2,2-Dimethylbutane:**
- Structure: CH₃-C(CH₃)₂-CH₂-CH₃
- Carbon environments: 2 types (1 primary and 1 tertiary).
- Number of monochloro derivatives = 2.

6. **Analyze 2,3-Dimethylbutane:**
- Structure: CH₃-CH(CH₃)-C(CH₃)-CH₃
- Carbon environments: 4 types (1 primary, 2 secondary, and 1 tertiary).
- Number of monochloro derivatives = 4.

7. **Analyze 3,3-Dimethylbutane:**
- Structure: CH₃-CH₂-C(CH₃)₂-CH₃
- Carbon environments: 2 types (1 primary and 1 tertiary).
- Number of monochloro derivatives = 2.

8. **Conclusion:**
After analyzing all the isomers, we find that both n-hexane and 2,2-dimethylbutane give the minimum number of monochloro derivatives, which is 2. However, since the question asks for the isomer that gives the minimum number of monochloro derivatives, we can conclude that the isomer with the least variety of carbon environments is **2,2-Dimethylbutane**.

### Final Answer:
The isomer of C₆H₁₄ that gives the minimum number of monochloro derivatives is **2,2-Dimethylbutane**.