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Saturday, 31 October

JEE Main · Chemistry · Hydrocarbons

Enumeration of Structural Isomers

JEE Main asked Enumeration of Structural Isomers 5 times in 5 of the 108 shifts Lumi analysed, in 2021, 2022, 2024 and 2026. It belongs to Structural Isomerism, in Hydrocarbons (Chemistry). The longest wait between two years asking it was 2 years. In 2022 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
5
in 5 shifts
Years
4 of 8
First asked
2021
last in 2026
Pattern
Frequent
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2021, 2022, 2024 and 2026. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.10.20’170’200.03’210.07’220’230.05’240’250.11’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 1 in 24 shifts · 2022: 2 in 24 shifts · 2023: 0 in 12 shifts · 2024: 1 in 18 shifts · 2025: 0 in 8 shifts · 2026: 1 in 9 shifts.

Shift by shift

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

  • 20261 of 9
  • 20250 of 8
  • 20241 of 18
  • 20230 of 12
  • 20222 of 24
  • 20211 of 24
  • 20200 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Numerical value is the usual form. Skill tested: multi-step.

  • Count monochloro products of isomers
  • Number of isomers of c7h16

Difficulty

Easy 0Medium 3Hard 2

5 of the 5 questions had a numerical answer.

Every question

All 5 questions

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

  1. 2 Apr 2026, Shift 1 · Q72Consider the isomers of hydrocarbon with molecular formula C5H10\mathrm{C_5H_{10}}. These isomers do not decolourise KMnO4\mathrm{KMnO_4}…HardNumerical value
  2. 4 Apr 2024, Shift 1 · Q88The number of different chain isomers for C7H16\mathrm{C_7H_{16}} is ________.MediumNumerical value
  3. 30 Jul 2022, Shift 2 · Q59The number of isomeric compounds (structural isomers only) possible with the molecular formula C5H10O2\mathrm{C_5H_{10}O_2}, which do not react…HardNumerical value
  4. 25 Jul 2022, Shift 2 · Q90The total number of monobromo derivatives formed by the alkanes with molecular formula C5H12\mathrm{C_5H_{12}} is (excluding stereo isomers)…MediumNumerical value
  5. 22 Jul 2021, Shift 2 · Q59The number of acyclic structural isomers (including geometrical isomers) for pentene are ________.MediumNumerical value

Shifts: 22 Jul 2021, Shift 2, 25 Jul 2022, Shift 2, 30 Jul 2022, Shift 2, 4 Apr 2024, Shift 1, 2 Apr 2026, Shift 1.

Same topic

Other ideas in Structural Isomerism

Structural Isomerism has 9 ideas JEE Main has asked; 2 of them came up in more than one question.

Topic analysisChapter analysisStudy this chapterAll repeated ideas