Question

What product is formed when sodium phenoxide reacts with ${\text{C}}{{\text{O}}_{\text{2}}}$ at 400K and ${\text{4}}{\text{.7}}$ atm pressure?
A.Sodium salicylate
B.Salicyl aldehyde
C.Benzoic acid
D.Benzaldehyde

Answer 1

In the above question, it is asked about the product formed when sodium phenoxide reacts with ${\text{C}}{{\text{O}}_{\text{2}}}$ at 400K and ${\text{4}}{\text{.7}}$ atm pressure. Kolbe-Scmitt reaction takes place here, the final product involves a carboxylic acid along with a phenoxide group.

Complete step-by-step answer: The reaction in which carboxylic acid is added onto the benzene ring of phenol or its derivative is known as Kolbe- Schmitt reaction.
The chemical formula of sodium phenoxide is ${{\text{C}}_{\text{6}}}{{\text{H}}_{\text{5}}}{\text{NaO}}$ and it is structurally represented as:
The reaction starts with deprotonation of sodium phenoxide leading to the formation of phenoxide ion. The negative charge on the oxygen atom makes the phenoxide more prone to electrophilic substitution reaction. The ${\text{C}}{{\text{O}}_{\text{2}}}$ which was added, now reacts with phenoxide ion to give a carboxylate. Addition of strong acid leads to protonation of the product formed and hence, the carboxylate ions get converted to carboxylic acid.
The whole process of reaction of sodium phenoxide with ${\text{C}}{{\text{O}}_{\text{2}}}$ is illustrated in the figure below:

Since, the final product formed is sodium salicylate. Hence, the correct option is option A.

Note: Since, sodium salicylate is the active component of aspirin. It is widely used for its anti-inflammatory, antipyretic and analgesic effects. It is also used for its inhibitory effect on platelet aggregation.
Sodium salicylate is useful as well as dangerous. It is quite dangerous if swallowed, harmful to the skin if absorbed through skin and causes eye irritation.