A chloro derivative (X) on treatment with Zn and HCl gave a hydrocarbon with five carbon atoms in the molecule when (X) is dissolved in ether and treated with Na, the product 2,2,5,5-tetra methyl hexane is obtained. The compound (X) is

Options

A. 3-chloro-2,2-dimethylpropane
B. 1-chloropropane
C. 1-chloro-2,2-dimethylpropane
D. 2-chloro-2-methylbutane

Answer

To solve the problem, we need to identify the chloro derivative (X) based on the information given about the products formed during the reactions.

### Step-by-Step Solution:

1. **Understanding the Reaction**:
- The chloro derivative (X) undergoes two reactions:
- First, it reacts with zinc (Zn) and hydrochloric acid (HCl) to yield a hydrocarbon with five carbon atoms.
- Second, when dissolved in ether and treated with sodium (Na), it produces 2,2,5,5-tetramethylhexane.

2. **Identifying the Hydrocarbon**:
- The hydrocarbon produced from the first reaction has five carbon atoms. The structure of 2,2,5,5-tetramethylhexane can be drawn as follows:
- The longest carbon chain consists of six carbons (hexane), with two methyl groups on the second carbon and two methyl groups on the fifth carbon.

3. **Constructing the Structure**:
- The structure of 2,2,5,5-tetramethylhexane is:
```
CH3
|
CH3 - C - CH2 - C - CH3
| |
CH3 CH3
```
- This indicates that the base structure is hexane, and we have two methyl groups on the second carbon and two on the fifth carbon.

4. **Determining the Chloro Derivative (X)**:
- To obtain 2,2,5,5-tetramethylhexane from a chloro derivative (X), we need to consider what alkyl halide would yield this product.
- The chloro derivative must have a structure that allows for the formation of the final hydrocarbon through the Wurtz reaction (which combines two alkyl halides).

5. **Finding the Alkyl Halide**:
- The simplest alkyl halide that can yield 2,2,5,5-tetramethylhexane is 1-chloro-2,2-dimethylpropane.
- This compound has three carbons in the main chain (propane) and two methyl groups on the second carbon.

6. **Final Answer**:
- Therefore, the compound (X) is **1-chloro-2,2-dimethylpropane**.

### Summary:
The compound (X) is **1-chloro-2,2-dimethylpropane**.