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Saturday, 31 October

JEE Main · Chemistry · Haloalkanes and Haloarenes

Enantiomeric Excess and Specific Rotation

JEE Main asked Enantiomeric Excess and Specific Rotation once in the 108 shifts Lumi analysed, on 27 Jul 2022, Shift 1. It belongs to Stereoisomerism, in Haloalkanes and Haloarenes (Chemistry).

Updated 2026-10-24

Times asked
1
in 1 shift
Years
1 of 8
First asked
2022
the only year
Pattern
Occasional
asked once so far

Questions on this idea a shift, by year

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

00.050.10’170’200’210.03’220’230’240’250’26

Raw count: 2017: 0 in 1 shift · 2020: 0 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
  • 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: calculation.

  • Optical purity from rotation

Difficulty

Easy 1Medium 0Hard 0

1 of the 1 question had a numerical answer.

Every question

The question

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

  1. 27 Jul 2022, Shift 1 · Q89Optical activity of an enantiomeric mixture is +12.6∘+12.6^\circ and the specific rotation of (+) isomer is +30∘+30^\circ. The optical purity is…EasyNumerical value

Shift: 27 Jul 2022, Shift 1.

Same topic

Other ideas in Stereoisomerism

Stereoisomerism has 11 ideas JEE Main has asked; 4 of them came up in more than one question.

Topic analysisChapter analysisStudy this chapterAll repeated ideas