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Saturday, 31 October

JEE Main 2021 · ChemistryMultiple choiceDiagram basedEasyApplication

JEE Main 4 August 2021, Shift 1, Chemistry Q45

Question 45 of 90 in this shift, Chemistry question 15 of 30, Section A.

Identify P in the given chemical reaction i) KMnO4\mathrm{KMnO_4}, KOH, heat ii) H3O+\mathrm{H_3O^+}

The figure, in words

Reactant: a benzene ring bonded to one carbon whose drawn labels are H (up), CH3 and H (down); reagents above/below the arrow: i) KMnO4, KOH, heat; ii) H3O+; product labelled P. Options are drawn as benzene rings with one substituent each: COOH, COCH3, CHO, and a two-carbon chain drawn as lines with a C=C double bond.
  1. (1)[figure: benzene ring bearing a COOH substituent]Official answer
  2. (2)[figure: benzene ring bearing a COCH3_3 substituent]
  3. (3)[figure: benzene ring bearing a CHO substituent]
  4. (4)[figure: benzene ring bearing a two-carbon chain drawn as lines, with a C=C double bond]

Official answer

Option 1

NTA final key.

Chapter
Aldehydes, Ketones and Carboxylic Acids
Topic
Aromatic Hydrocarbons
Idea tested
Side-chain Oxidation

Same idea in other shifts

Asked 6× in all
  1. 4 Apr 2026, Shift 1 · Q72Consider the following sequence of reactions to give the major product (X) benzene…MediumNumerical valueHas a figure
  2. 5 Apr 2024, Shift 2 · Q89The product (C) in the following sequence of reactions has ________ π\pi bonds. n-propylbenzene (benzene ring bearing a three-carbon…MediumNumerical valueHas a figure
  3. 30 Jan 2024, Shift 1 · Q75In the given reactions, identify the reagent A and reagent B. [Scheme: toluene reacts via two routes to give benzaldehyde. Route 1: "A" +…MediumOtherHas a figure
  4. 10 Apr 2023, Shift 1 · Q74The major product ‘P’ formed in the given reaction is [structure: naphthalene ring bearing CH2CH3\mathrm{CH_2CH_3} at one position of one…MediumDiagram basedHas a figure
  5. 26 Jun 2022, Shift 2 · Q72Oxidation of toluene to benzaldehyde can be easily carried out with which of the following reagents?MediumSingle correct

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.