Learn

Saturday, 31 October

JEE Main 2022 · ChemistryMultiple choiceDiagram basedMediumApplication

JEE Main 27 July 2022, Shift 2, Chemistry Q72

Question 72 of 90 in this shift, Chemistry question 12 of 30, Section A.

The structure of A in the given reaction is : [figure: R-C(=O)-CH3 treated with NaOH and CH3CH2-Br (drawn as zigzag line with Br); product A (major product)]

The figure, in words

Reaction scheme: R-CO-CH3 with NaOH and an ethyl bromide drawn as a zigzag line with Br, giving A (major product). Options are structures.
  1. (1)[figure: R−C(OH)(CH3)−CH(Br)−CH3\mathrm{R-C(OH)(CH_3)-CH(Br)-CH_3}, i.e. R, OH and CH3 on one carbon bonded to a carbon bearing Br and H3C]
  2. (2)[figure: R−C(OH)(CH3)−CH2CH3\mathrm{R-C(OH)(CH_3)-CH_2CH_3}]
  3. (3)[figure: R-C(=O)- zigzag chain of three further carbons, i.e. R−CO−CH2CH2CH3\mathrm{R-CO-CH_2CH_2CH_3}]Official answer
  4. (4)[figure: R-C(=O)- zigzag chain ending in OH]

Official answer

Option 3

NTA final key.

Chapter
Aldehydes, Ketones and Carboxylic Acids
Topic
Aldol and Cannizzaro
Idea tested
Alpha-Hydrogen Acidity

Same idea in other shifts

Asked 2× in all
  1. 2 Apr 2025, Shift 1 · Q68Given below are two statements : Statement (I) : Vanillin ([structure: benzene ring with -CHO, -OH para to CHO and -OCH3 ortho to OH])…MediumTwo statementsHas 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.