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Saturday, 31 October

JEE Main 2020 · ChemistryMultiple choiceOtherMediumConceptual

JEE Main 5 September 2020, Shift 1, Chemistry Q31

Question 31 of 75 in this shift, Chemistry question 6 of 25.

Which of the following derivatives of alcohols is unstable in an aqueous base ?

The figure, in words

All four options are drawn structures with RO as printed; see option text.
  1. (1)[structure] RO attached to a carbon bearing =O and MeOfficial answer
  2. (2)RO−CMe3\mathrm{RO-CMe_3}
  3. (3)[structure] RO bonded to a CH2_2 line vertex attached to a six-membered ring drawn with an inner circle
  4. (4)[structure] RO attached to a carbon of a six-membered ring that contains an O atom (the carbon is next to the ring O)

Official answer

Option 1

NTA final key (Sep 2020).

Chapter
Alcohols, Phenols and Ethers
Topic
Carboxylic Acids and Derivatives
Idea tested
Saponification Mechanism and Kinetics

Same topic in other shifts

All Carboxylic Acids and Derivatives questions
  1. 5 Apr 2026, Shift 2 · Q65Complete the following reaction sequence and give the name of major product 'P'. CH3CH2C≡N\mathrm{CH_3CH_2C{\equiv}N}…MediumSingle correctHas a figure
  2. 8 Apr 2026, Shift 2 · Q67Consider the following reaction. [figure: N-substituted 2-piperidone (six-membered lactam, C=O adjacent to ring N) with N bonded to…HardDiagram basedHas a figure
  3. 2 Apr 2025, Shift 1 · Q67Consider the following molecules : (p) CH3−CH2−C(=O)−Cl\mathrm{CH_3-CH_2-C(=O)-Cl} (q) CH3−CH2−C(=O)−O−C(=O)−CH3\mathrm{CH_3-CH_2-C(=O)-O-C(=O)-CH_3} (r)…EasySingle correctHas a figure
  4. 2 Apr 2025, Shift 2 · Q68Consider the following reactions. From these reactions which reaction will give carboxylic acid as a major product ? (A)…MediumOtherHas a figure
  5. 8 Apr 2025, Shift 2 · Q69A→(ii) H3O+(i) NaOHB→(ii) H2SO4,Δ(i) EtOHCA \xrightarrow[\text{(ii) H}_3\text{O}^+]{\text{(i) NaOH}} B \xrightarrow[\text{(ii) H}_2\text{SO}_4, \Delta]{\text{(i) EtOH}} C 'A'…MediumSingle correctHas a figure
  6. 8 Apr 2024, Shift 1 · Q79Identify the product (P) in the following reaction: [figure: cyclopentanecarboxylic acid]…EasyDiagram 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. 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.