NEETChemistryCarboxylic Acid Derivatives
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): tert -Butylbenzene undergoes oxidation to benzoic acid when heated with alkaline KMnO₄ . Reason (R): The oxidation of an alkylbenzene to benzoic acid requires the presence of at least one benzylic hydrogen atom on the alkyl chain. In the light of the above statements, choose the correct answer from
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is false
- D(A) is false but (R) is true
Correct answer
D. (A) is false but (R) is true
Step-by-step solution
Assertion (A) is false. tert -Butylbenzene does not undergo oxidation to benzoic acid when heated with alkaline KMnO₄ . Reason (R) is true. For an alkylbenzene to be oxidized to benzoic acid by strong oxidizing agents like alkaline KMnO₄ , the alkyl group must have at least one benzylic hydrogen atom. In tert -butylbenzene, the benzylic carbon is attached to three methyl groups and has no benzylic hydrogen atoms. Therefore, it resists oxidation. Hence, (A) is false but (R) is true. Answer: (A) is false but (R) is t