Learn

Saturday, 31 October

JEE Main 2024 · ChemistryMultiple choiceSingle correctEasyConceptual

JEE Main 30 January 2024, Shift 2, Chemistry Q73

Question 73 of 90 in this shift, Chemistry question 13 of 30, Section A.

The correct stability order of carbocations is
  1. (1)+CH3>CH3−+CH2>CH3−+CH−CH3>(CH3)3C+\mathrm{{}^+CH_3} > \mathrm{CH_3-{}^+CH_2} > \mathrm{CH_3-{}^+CH-CH_3} > \mathrm{(CH_3)_3C^+}
  2. (2)+CH3>(CH3)2+CH>CH3−+CH2>(CH3)3+C\mathrm{{}^+CH_3} > \mathrm{(CH_3)_2{}^+CH} > \mathrm{CH_3-{}^+CH_2} > \mathrm{(CH_3)_3{}^+C}
  3. (3)(CH3)3+C>(CH3)2+CH>CH3−+CH2>+CH3\mathrm{(CH_3)_3{}^+C} > \mathrm{(CH_3)_2{}^+CH} > \mathrm{CH_3-{}^+CH_2} > \mathrm{{}^+CH_3}Official answer
  4. (4)(CH3)3C+>CH3−+CH2>(CH3)2+CH>+CH3\mathrm{(CH_3)_3C^+} > \mathrm{CH_3-{}^+CH_2} > \mathrm{(CH_3)_2{}^+CH} > \mathrm{{}^+CH_3}

Official answer

Option 3

NTA final key.

Chapter
Organic Chemistry: Some Basic Principles and Techniques
Topic
Inductive and Electromeric Effects
Idea tested
Carbocation Stability

Same idea in other shifts

Asked 4× in all
  1. 4 Apr 2025, Shift 2 · Q63In which pairs, the first ion is more stable than the second ? (A) [figure: 1-methoxycyclohexyl cation] & [figure: 1-methylcyclohexyl…MediumOtherHas a figure
  2. 10 Apr 2023, Shift 2 · Q73The decreasing order of hydride affinity for following carbocations is: A. CH2=CH−C+(CH3)−CH3\mathrm{CH_2=CH-\overset{+}{C}(CH_3)-CH_3} (carbocation…HardOtherHas a figure
  3. 24 Jun 2022, Shift 2 · Q73Arrange the following carbocations in decreasing order of stability.HardDiagram basedHas 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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.