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Saturday, 31 October

JEE Main 2021 · ChemistryMultiple choiceSingle correctEasyConceptual

JEE Main 25 July 2021, Shift 2, Chemistry Q44

Question 44 of 90 in this shift, Chemistry question 14 of 30, Section A.

[figure: structure labelled "Maleic anhydride"] Maleic anhydride can be prepared by :

The figure, in words

Drawn above the question and labelled "Maleic anhydride": a five-membered ring containing one ring O (at right), a double bond on the left side of the ring, and two carbonyl groups (C=O, with O printed at top and bottom) on the two ring carbons attached to the ring O.
  1. (1)Heating trans-but-2-enedioic acid
  2. (2)Heating cis-but-2-enedioic acidOfficial answer
  3. (3)Treating trans-but-2-enedioic acid with alcohol and acid
  4. (4)Treating cis-but-2-enedioic acid with alcohol and acid

Official answer

Option 2

NTA final key.

Chapter
Aldehydes, Ketones and Carboxylic Acids
Topic
Carboxylic Acids and Derivatives
Idea tested
Heating Effects on Dicarboxylic Acids

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.