What are the products obtained in the chemical reaction?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Phenol (A) + Acetone (B)
The starting compound is cumene (isopropylbenzene). Air oxidation gives cumene hydroperoxide, which is cleaved by dilute acid:
\( \ce{C6H5CH(CH3)2} \xrightarrow{\ce{O2}} \ce{C6H5C(CH3)2OOH} \xrightarrow{\ce{H+/H2O}} \ce{C6H5OH} + \ce{CH3COCH3} \)
A = phenol, B = acetone (propanone).
Why the other options are incorrect
Option (2) — Incorrect. Gives acetaldehyde (\( \ce{CH3CHO} \)) as B; the two-carbon fragment would not account for the three side-chain carbons.
Option (3) — Incorrect. It gives acetophenone as A; the reaction gives phenol, with the –OH group on the ring, not a ketone.
Option (4) — Incorrect. It also gives acetophenone as A; no ketone is formed on the ring carbon.
NCERT (2026-27 edition):
From Cumene – “Phenol is manufactured from the hydrocarbon, cumene. Cumene (isopropylbenzene) is oxidised in the presence of air to cumene hydroperoxide. It is converted to phenol and acetone by treating it with dilute acid. Acetone, a by-product of this reaction, is also obtained in large quantities by this method.”