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Saturday, 31 October

JEE Main 2022 · ChemistryMultiple choiceDiagram basedEasyMulti-step

JEE Main 28 July 2022, Shift 2, Chemistry Q44

Question 44 of 90 in this shift, Chemistry question 14 of 30, Section A.

Compound I is heated with Conc. HI to give a hydroxy compound A which is further heated with Zn dust to give compound B. Identify A and B. [Compound I: isopropyl phenyl ether, drawn as a benzene ring bonded to O, which is bonded to an isopropyl group] →ΔConc. HI\xrightarrow[\Delta]{\text{Conc. HI}} A →Zn, Δ\xrightarrow{\mathrm{Zn},\ \Delta} B

The figure, in words

Compound I is a benzene ring bonded through O to an isopropyl group (aryl isopropyl ether), labelled I. Reagents: Conc. HI, heat gives A; then Zn, heat gives B.
  1. (1)A = [isopropyl alcohol (propan-2-ol)], B = [propane]
  2. (2)A = [phenol], B = [p-benzoquinone, ring with two C=O at para positions]
  3. (3)A = [2-isopropylphenol, OH and isopropyl on adjacent ring carbons], B = [isopropylbenzene (cumene)]
  4. (4)A = [phenol, OH drawn as substituent on ring], B = [benzene]Official answer

Official answer

Option 4

NTA final key.

Chapter
Alcohols, Phenols and Ethers
Topic
Ethers
Idea tested
Cleavage of Alkyl-Aryl Ethers

Same idea in other shifts

Asked 3× in all
  1. 29 Jan 2024, Shift 1 · Q77The major product (P) in the following reaction isMediumDiagram basedHas a figure
  2. 18 Mar 2021, Shift 2 · Q44Main Products formed during a reaction of 1-methoxy naphthalene with hydroiodic acid are :EasySingle correctHas a figure

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.