Which alkane cannot be be produced using only one type of alkyl halide in Wurtz reaction?

Options

A. `CH_3-CH_3`
B. `Ch_3CH_2CH_2CH_3`
C. `CH_3CH_2CH_2CH_2CH_3`
D.

Answer

To determine which alkane cannot be produced using only one type of alkyl halide in the Wurtz reaction, we first need to understand the Wurtz reaction itself. The Wurtz reaction involves the coupling of two alkyl halides in the presence of sodium metal, leading to the formation of alkanes.

### Step-by-Step Solution:

1. **Understand the Wurtz Reaction**:
The Wurtz reaction is a coupling reaction where two alkyl halides react with sodium to form a higher alkane. The general reaction can be represented as:
\[ 2 R-X + 2 Na \rightarrow R-R + 2 NaX \]
where \( R \) is the alkyl group and \( X \) is the halide.

2. **Identify the Alkane Types**:
We need to analyze the alkanes that can be formed from different alkyl halides. The alkanes can vary in carbon chain length and branching.

3. **Consider the Alkyl Halides**:
If we use a single type of alkyl halide (for example, only ethyl bromide), we can only form alkanes that are multiples of the carbon chain length of the alkyl halide used. For example:
- Using ethyl bromide (C2H5Br) will yield butane (C4H10) as:
\[ 2 C_2H_5Br + 2 Na \rightarrow C_4H_{10} + 2 NaBr \]

4. **Identify Limitations**:
However, if we try to produce an alkane with an odd number of carbon atoms (like propane, C3H8), we cannot achieve this using only one type of alkyl halide. This is because the Wurtz reaction requires two alkyl halides to couple, and two even-numbered alkyl groups will always yield an even-numbered alkane.

5. **Conclusion**:
Therefore, the alkane that cannot be produced using only one type of alkyl halide in the Wurtz reaction is **propane (C3H8)**, as it requires a combination of different alkyl halides to achieve an odd-numbered carbon count.

### Final Answer:
**Propane (C3H8) cannot be produced using only one type of alkyl halide in the Wurtz reaction.**