Question

How to convert benzoic acid to benzene?

Answer 1

Hint: The conversion of benzoic acid to benzene is an example of decarboxylation reaction. The structure of benzoic acid and benzene are as follows.

Complete answer:
- In the question it asked to convert the benzoic acid to benzene.
- The conversion of benzoic acid to benzene is a two-step process.
- In the first step benzoic acid is going to convert into sodium benzoate and in the second step the sodium benzoate is going to be converted into benzene on reaction with water.
Step-1:
- In the first step the conversion of benzoic acid to sodium benzoate is going to occur by the usage of the sodium hydroxide in the presence of calcium oxide.
- The combination of sodium hydroxide with calcium oxide is known as soda lime.
- The chemical reaction of converting benzoic acid to sodium benzoate in the presence of soda lime is as follows.

Step-2:
- In this step the sodium benzoate will undergo hydrolysis with water and forms benzene as a product.
- The chemical reaction of sodium benzoate into benzene is as follows.

Note:
All the organic compounds that contain carboxylic acid functional groups easily undergo decarboxylation and form the respective hydrocarbon as the product. We can prepare benzene from phenol also. In the conversion of phenol to benzene there is a role of zinc dust in the presence of heat. That means benzene can be prepared in two ways.