Question

In Kolbe's reaction the reacting substances are

• A. Sodium phenate and CCl4
• B. Sodium phenate and CO2
• C. Phenol and CHCl3
• D. Phenol and CCl4

Answer 1

Answer: (B)

Sodium phenate and CO2

Answer 2

Kolbe's reaction involves the electrolysis of a sodium phenate solution in the presence of carbon dioxide $(CO_2)$.
Sodium phenate is derived from phenol $(\text{C}_6\text{H}_5\text{OH})$ by treating it with sodium hydroxide $(NaOH)$. When sodium phenate is electrolyzed, it undergoes decarboxylation in the presence of CO2, resulting in the formation of sodium salicylate.
The reaction can be represented as follows:
$2 \text{C}_6\text{H}_5\text{ONa} + 2 \text{CO}_2 \rightarrow 2 \text{C}_7\text{H}_5\text{O}_3\text{Na} + \text{O}_2$
This reaction is an important step in the synthesis of salicylic acid and related compounds.
Therefore, the correct reacting substances in Kolbe's reaction are sodium phenate and CO2 (option B).