Question

Which is the correct option for the following reaction? \[ 2\,\text{CH}_3\text{CH}_2\text{Br} \xrightarrow{\text{2Na/Dry ether}} \text{?} \]

• A. Wurtz reaction: CH$_3$CH$_2$CH$_2$CH$_3$
• B. Wurtz-Fitting reaction: CH$_3$CH$_2$CH$_2$CH$_3$
• C. Wurtz reaction: CH$_3$CH$_2$CH$_2$CH$_2$CH$_3$
• D. Wurtz-Fitting reaction: CH$_3$CH$_2$CH$_2$CH$_2$CH$_3$

Hint:

$\textbf{Remember:}$ - Wurtz: 2R-X → R-R - Wurtz-Fittig: R-X + Ar-X → R-Ar

Answer 1

The Correct Option is A

This is a Wurtz reaction where two ethyl bromide molecules couple to form butane \(CH_3-CH_2-CH_2-CH_3\). 
Key points: 
- Wurtz reaction combines two identical alkyl halides 
- Produces symmetrical alkanes (here: butane) 
- Uses Na/dry ether conditions 
- Wurtz-Fittig requires an aryl halide (not present here) 
- Pentane would require different reactants

Answer 2

Step 1: Identify the reaction type.
The reaction given is:
\[ 2\,\text{CH}_3\text{CH}_2\text{Br} \xrightarrow{\text{2Na/Dry ether}} ? \] This is a classic example of the Wurtz reaction, where alkyl halides react with sodium metal in dry ether.

Step 2: Mechanism of the Wurtz reaction.
- Sodium metal donates electrons to the alkyl halide, generating alkyl radicals.
- Two alkyl radicals couple together, forming a new carbon-carbon bond.

Step 3: Predict the product.
Since the starting material is ethyl bromide (\(\text{CH}_3\text{CH}_2\text{Br}\)), coupling two ethyl groups gives:
\[ \text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3, \] which is butane.

Step 4: Conclusion.
Therefore, the product of the Wurtz reaction with ethyl bromide is butane, and the correct option is:
\[ \text{Wurtz reaction: } \text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3. \]