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Saturday, 31 October

JEE Main · Chemistry · Aldehydes, Ketones and Carboxylic Acids

Decarboxylation Reactions

JEE Main asked Decarboxylation Reactions 2 times in 2 of the 108 shifts Lumi analysed, in 2020 and 2022. It belongs to Carboxylic Acids and Derivatives, in Aldehydes, Ketones and Carboxylic Acids (Chemistry). The longest wait between two years asking it was 2 years.

Updated 2026-10-24

Times asked
2
in 2 shifts
Years
2 of 8
First asked
2020
last in 2022
Pattern
Occasional
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2020 and 2022. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.050.10’170.08’200’210.03’220’230’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 1 in 12 shifts · 2021: 0 in 24 shifts · 2022: 1 in 24 shifts · 2023: 0 in 12 shifts · 2024: 0 in 18 shifts · 2025: 0 in 8 shifts · 2026: 0 in 9 shifts.

Shift by shift

Each square is one analysed shift, in date order. Open a filled one for that paper.

  • 20260 of 9
  • 20250 of 8
  • 20240 of 18
  • 20230 of 12
  • 20221 of 24
  • 20210 of 24
  • 20201 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Diagram based is the usual form. Skill tested: multi-step.

  • Predict product of reaction sequence
  • Identify compound from reactions of aromatic acid

Difficulty

Easy 0Medium 2Hard 0

Every question was multiple choice.

Every question

All 2 questions

From the official JEE Main shift papers, newest first. Open one for the full question, the options and the official answer.

  1. 24 Jun 2022, Shift 2 · Q76Hex-4-ene-2-ol on treatment with PCC gives 'A'. 'A' on reaction with sodium hypoiodite gives 'B', which on further heating with soda lime…MediumSingle correct
  2. 4 Sep 2020, Shift 1 · Q43[P] on treatment with Br2/FeBr3\mathrm{Br_2/FeBr_3} in CCl4\mathrm{CCl_4} produced a single isomer C8H7O2Br\mathrm{C_8H_7O_2Br} while heating [P] with…MediumDiagram basedHas a figure

Shifts: 4 Sep 2020, Shift 1, 24 Jun 2022, Shift 2.

Same topic

Other ideas in Carboxylic Acids and Derivatives

Carboxylic Acids and Derivatives has 15 ideas JEE Main has asked; 11 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas