Sodium salt of benzoic acid on heating with sodalime gives:

Question

Accepted Answer

Sodium salt of benzoic acid, when heated with sodalime, undergoes a decarboxylation reaction. Sodalime is a mixture of sodium hydroxide (NaOH) and calcium oxide (CaO), which facilitates the removal of the carboxyl group from the benzoic acid salt. This process results in the formation of benzene.

1. **Explanation for Option 1 (Benzene):**
   - The reaction of sodium benzoate (sodium salt of benzoic acid) with sodalime leads to the removal of the carboxyl group as carbon dioxide (CO₂), leaving behind the benzene ring. This is a classic example of a decarboxylation reaction, where the carboxyl group is removed, and the hydrogen atom takes its place, forming benzene. The reaction can be represented as:
     $$
     \text{C}_6\text{H}_5\text{COONa} + \text{NaOH} \xrightarrow{\text{CaO, heat}} \text{C}_6\text{H}_6 + \text{Na}_2\text{CO}_3
     $$
   - Therefore, the correct product of this reaction is benzene, which supports Option 1 as the correct answer.

2. **Explanation for why other options are incorrect:**
   - **Option 2 (Sodium benzoate):** Sodium benzoate is the starting material, not the product. The reaction involves the conversion of sodium benzoate into benzene, so sodium benzoate cannot be the product.
   - **Option 3 (Phenol):** Phenol is not formed in this reaction. Phenol would require the introduction of an -OH group, which is not facilitated by the sodalime decarboxylation process.
   - **Option 4 (Toluene):** Toluene is not produced in this reaction. Toluene has a methyl group attached to the benzene ring, which is not introduced in the decarboxylation of sodium benzoate with sodalime.

In conclusion, the reaction of sodium salt of benzoic acid with sodalime results in the formation of benzene, making Option 1 the correct answer.