Learn

Saturday, 31 October

JEE Main 2024 · ChemistryMultiple choiceDiagram basedEasyConceptual

JEE Main 27 January 2024, Shift 1, Chemistry Q72

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

Which of the following has highly acidic hydrogen ?

The figure, in words

Options are skeletal/condensed structures: (1) single ketone, zig-zag chain, H3C at left and CH3 at right with C=O drawn below; (2) H3C-C(=O)-CH2-C(=O)-CH2-CH3; (3) H3C-C(=O)-CH2-CH2-C(=O)-CH3; (4) H3C-C(=O)-C(=O)-CH2-CH2-CH3.
  1. (1)[figure: skeletal mono-ketone, H3C at left end, C=O in the middle, CH3 at right end]
  2. (2)[figure: H3C−CO−CH2−CO−CH2CH3\mathrm{H_3C-CO-CH_2-CO-CH_2CH_3}, 1,3-diketone]Official answer
  3. (3)[figure: H3C−CO−CH2−CH2−CO−CH3\mathrm{H_3C-CO-CH_2-CH_2-CO-CH_3}, 1,4-diketone]
  4. (4)[figure: H3C−CO−CO−CH2CH2CH3\mathrm{H_3C-CO-CO-CH_2CH_2CH_3}, 1,2-diketone]

Official answer

Option 2

NTA final key.

Chapter
Aldehydes, Ketones and Carboxylic Acids
Topic
Organic Acidity and Basicity
Idea tested
Acidity of Active Methylene Compounds

Same idea in other shifts

Asked 2× in all
  1. 3 Sep 2020, Shift 1 · Q39Which one of the following compounds possesses the most acidic hydrogen ?MediumSingle 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.