NEETChemistryAlcohols Phenols and Ethers
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Phenol undergoes electrophilic substitution with carbon dioxide to form ortho-hydroxybenzoic acid as the main product in Kolbe's reaction. Reason (R): The phenoxide ion, generated by treating phenol with NaOH, is more reactive than phenol towards electrophilic aromatic substitution. In the light of
Options
- ABoth Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation of Assertion (A)
- BBoth Assertion (A) and Reason (R) are correct but Reason (R) is not the correct explanation of Assertion (A)
- CAssertion (A) is correct but Reason (R) is incorrect
- DAssertion (A) is incorrect but Reason (R) is correct
Correct answer
A. Both Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation of Assertion (A)
Step-by-step solution
Assertion (A) is correct: In Kolbe's reaction, phenol is treated with NaOH and then with CO ₂ followed by acidification to yield ortho-hydroxybenzoic acid (salicylic acid) as the major product. Reason (R) is correct: The phenoxide ion formed by the action of NaOH on phenol is highly activating. It is even more reactive than phenol towards electrophilic aromatic substitution. Reason (R) correctly explains Assertion (A): It is precisely this enhanced reactivity of the phenoxide ion that allows it to undergo electroph