Which of the following hydrocarbons is not formed when Wurtz reaction takes place between ethyl iodide and propyl iodide?

Options

A. Butane
B. Propane
C. Pentane
D. Hexane

Answer

To solve the question of which hydrocarbon is not formed when Wurtz reaction takes place between ethyl iodide and propyl iodide, we will follow these steps:

### Step-by-Step Solution:

1. **Understand the Wurtz Reaction**:
The Wurtz reaction involves the coupling of alkyl halides in the presence of sodium metal and dry ether. This reaction leads to the formation of higher alkanes.

2. **Identify the Reactants**:
The reactants given are ethyl iodide (C2H5I) and propyl iodide (C3H7I).

3. **Write the Structures**:
- Ethyl iodide: C2H5I can be represented as CH3-CH2-I.
- Propyl iodide: C3H7I can be represented as CH3-CH2-CH2-I.

4. **Possible Coupling Reactions**:
When these two alkyl halides react, they can couple in different ways:
- **Coupling of two ethyl radicals**:
\[ 2 \text{C2H5} \rightarrow \text{C4H10} \quad (\text{Butane}) \]
- **Coupling of two propyl radicals**:
\[ 2 \text{C3H7} \rightarrow \text{C6H14} \quad (\text{Hexane}) \]
- **Coupling of one ethyl and one propyl radical**:
\[ \text{C2H5} + \text{C3H7} \rightarrow \text{C5H12} \quad (\text{Pentane}) \]

5. **List the Products**:
From the above reactions, we can conclude that the following hydrocarbons are formed:
- Butane (C4H10)
- Pentane (C5H12)
- Hexane (C6H14)

6. **Identify the Hydrocarbon Not Formed**:
The question asks which hydrocarbon is NOT formed. Among the hydrocarbons listed (butane, pentane, hexane), the only one that does not appear is propane (C3H8).

### Conclusion:
The hydrocarbon that is not formed when ethyl iodide and propyl iodide undergo Wurtz reaction is **propane (C3H8)**.