JEE Advanced 2024 · Paper 1 · Chemistry Q6

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ChemistryMultiple correct+4 / -2Question 40 of 51

Reaction of iso-propylbenzene with $\ce{O2}$ followed by the treatment with $\ce{H3O+}$ forms phenol and a by-product P. Reaction of P with 3 equivalents of $\ce{Cl2}$ gives compound Q. Treatment of Q with $\ce{Ca(OH)2}$ produces compound R and calcium salt S.

The correct statement(s) regarding P, Q, R and S is(are)

Reaction of P with R in the presence of KOH followed by acidification gives

A tertiary alcohol: a central carbon bearing OH, CCl₃ and two CH₃ groups, i.e. 1,1,1-trichloro-2-methylpropan-2-ol, (CH₃)₂C(OH)CCl₃.

Reaction of R with

\ce{O2}

in the presence of light gives phosgene gas

Q reacts with aqueous NaOH to produce

\ce{Cl3CCH2OH}

and

\ce{Cl3CCOONa}

S on heating gives P

Answer and worked solution

Official answer: A, B, D

Cumene process: phenol + acetone, so P = $\ce{CH3COCH3}$ .

$\ce{CH3COCH3 + 3Cl2 -> CCl3COCH3}$ (Q). The haloform cleavage with $\ce{Ca(OH)2}$ gives $\ce{CHCl3}$ (R) and $\ce{(CH3COO)2Ca}$ (S).

(A) True: $\ce{CH3COCH3 + CHCl3 ->[KOH] (CH3)2C(OH)CCl3}$ (chloretone).
(B) True: $\ce{2CHCl3 + O2 ->[h\nu] 2COCl2 + 2HCl}$ , i.e. phosgene.
(C) False: Q with NaOH gives $\ce{CHCl3}$ and $\ce{CH3COONa}$ .
(D) True: $\ce{(CH3COO)2Ca ->[\Delta] CH3COCH3 + CaCO3}$ .

Topics:Named reactions Phenols Polyhalogen compounds

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JEE Advanced 2024 · Paper 1, Chemistry question 6