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Saturday, 31 October

JEE Main · Chemistry · Aldehydes, Ketones and Carboxylic Acids

Iodoform Test for Specific Alcohols

JEE Main asked Iodoform Test for Specific Alcohols 5 times in 5 of the 108 shifts Lumi analysed, in 2022, 2023, 2024 and 2025. It belongs to Alcohols and Phenols, in Aldehydes, Ketones and Carboxylic Acids (Chemistry). The longest wait between two years asking it was 1 year. In 2025 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
2022
last in 2025
Pattern
Comes in cycles
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2022, 2023, 2024 and 2025. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.150.30’170’200’210.03’220.07’230.05’240.25’250’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 0 in 24 shifts · 2022: 1 in 24 shifts · 2023: 1 in 12 shifts · 2024: 1 in 18 shifts · 2025: 2 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
  • 20252 of 8
  • 20241 of 18
  • 20231 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: multi-step.

  • True statement selection on iodoform test
  • Count compounds failing a named test

Difficulty

Easy 2Medium 3Hard 0

2 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. 4 Apr 2025, Shift 2 · Q67Which among the following compounds give yellow solid when reacted with NaOI/NaOH ? (A) CH3−CH(OH)−C2H5\mathrm{CH_3-CH(OH)-C_2H_5} (B)…EasyOther
  2. 3 Apr 2025, Shift 1 · Q68Number of molecules from below which cannot give iodoform reaction is: Ethanol, Isopropyl alcohol, Bromoacetone, 2−-Butanol,…MediumSingle correct
  3. 9 Apr 2024, Shift 2 · Q78Which of the following compound can give positive iodoform test when treated with aqueous KOH solution followed by potassium hypoiodite.MediumSingle correctHas a figure
  4. 6 Apr 2023, Shift 2 · Q89Among the following, the number of compounds which will give positive iodoform reaction is ______________. (a) 1-Phenylbutan-2-one (b)…MediumNumerical value
  5. 29 Jun 2022, Shift 1 · Q90C6H12O6→ZymaseA→ΔNaOIB+CHI3\mathrm{C_6H_{12}O_6 \xrightarrow{Zymase} A \xrightarrow[\Delta]{NaOI} B + CHI_3} The number of carbon atoms present in the product B is…EasyNumerical value

Shifts: 29 Jun 2022, Shift 1, 6 Apr 2023, Shift 2, 9 Apr 2024, Shift 2, 3 Apr 2025, Shift 1, 4 Apr 2025, Shift 2.

Same topic

Other ideas in Alcohols and Phenols

Alcohols and Phenols has 26 ideas JEE Main has asked; 13 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas