Question

Question 13.25 Why is Wurtz reaction not preferred for the preparation of alkanes containing odd number of carbon atoms? Illustrate your answer by taking one example.

Class XI Hydrocarbons Page 397

Answer 1

In Wurtz reaction, when preferred for the preparation of alkanes containing odd number of carbon atoms , then it means two different alkyl halides are taken and two different alkyl halides can react in three different ways. Therefore a mixture of alkanes is produced .
That's why Wurtz reaction doesn't suitable for the preparation of alkanes containing odd number of carbon atoms .

For batter understanding ,see the example shown in figure .here two different alkyl halides , CH3I and C2H5I are taken for the preparation of the alkanes . But we observed, alkanes are the mixture of Ethane , propane and butane .

Answer 2

Explanation:

for product of alkane containing odd no of carbons , the reactants will be two different alkyl halides. when two different alkyl halides reacts ,then mixture of alkanes formed. thats why wurtz reaction is not preferred for the preparation of alkanes containing odd no of carbons.

example of reaction of two different alkyl halides with sodium .

3CH3I + 4C2H5I + 6Na --> CH3CH3 + C2H5CH3 + C2H5C2H5 + 6NaI