Question

Identify a CORRECT statement about the preparation of alkanes from the following:  

Options

• Alkanes containing even a number of carbon atoms cannot be obtained in pure form by the Wurtz reaction. 

• Methane cannot be prepared by catalytic hydrogenation of alkenes. 

• The alkanes formed by the reduction of carboxylic acids contain one carbon atom less than the carboxylic acid. 

• Corey-House reaction involves the conversion of amides to alkanes by using lithium and copper iodide. 

Answer 1

Methane cannot be prepared by catalytic hydrogenation of alkenes. 

Explanation:

1. By Wurtz reaction, odd-number carbon atom alkanes cannot be produced in pure form.
2. Neither the Wurtz reaction nor the catalytic hydrogenation of alkenes can produce methane.
3. The alkanes produced when carboxylic acids are reduced have an identical number of carbon atoms as the original carboxylic acid. The alkanes created by decarboxylation of carboxylic acids, on the other hand, have one less carbon atom than a carboxylic acid.
4. In the Corey-House reaction, lithium and copper iodide are used to convert alkyl halides to alkanes.