MCQ Detailed View

The Wurtz synthesis is a well-known organic reaction used for the preparation of higher alkanes. In this method, two alkyl halide molecules react with metallic sodium in the presence of dry ether to form a new carbon–carbon bond. The general reaction can be written as:

2 R–X + 2 Na → R–R + 2 NaX

Here, R–X represents an alkyl halide (e.g., methyl chloride, ethyl bromide), Na is metallic sodium, and R–R is the alkane formed after coupling.

One of the most important conditions for carrying out this synthesis is the use of dry diethyl ether as the reaction medium. The reasons are:

1. 
   

   Solvent stability – Diethyl ether is relatively inert under the reaction conditions and does not interfere with sodium or the alkyl halides.

   
   


2. 
   

   Solubility – It effectively dissolves both the sodium metal (surface contact) and the alkyl halides, allowing the reaction to proceed smoothly.

   
   


3. 
   

   Water-free environment – The ether used must be absolutely dry because even small traces of water or alcohol would react with sodium, destroying the reagent and stopping the reaction.

   
   

Diethyl ether is therefore the solvent of choice for Wurtz synthesis. Other ethers, such as dimethyl ether or phenyl ether, are not suitable due to their reactivity or physical properties.

This reaction is commonly used to synthesize symmetrical alkanes such as ethane, butane, or hexane from smaller alkyl halides. However, it has limited scope because it mainly works for primary alkyl halides and produces mixtures when different alkyl halides are used.

Thus, the correct answer is diethyl ether, which provides the essential inert and anhydrous medium for the reaction.