Learn

Saturday, 31 October

JEE Main 2024 · ChemistryMultiple choiceDiagram basedEasyRecall

JEE Main 8 April 2024, Shift 1, Chemistry Q79

Question 79 of 90 in this shift, Chemistry question 19 of 30, Section A.

Identify the product (P) in the following reaction: [figure: cyclopentanecarboxylic acid] →ii) H2Oi) Br2/Red P\xrightarrow[\text{ii) }\mathrm{H_2O}]{\text{i) }\mathrm{Br_2/Red\ P}} (P)

The figure, in words

Cyclopentane ring bearing COOH treated with (i) Br2/red P, (ii) H2O giving product P.
  1. (1)[figure: 1-bromocyclopentane-1-carboxylic acid (COOH\mathrm{COOH} and Br on the same ring carbon)]Official answer
  2. (2)[figure: cyclopentanecarbonyl bromide (COBr\mathrm{COBr})]
  3. (3)[figure: 2-bromocyclopentane-1-carboxylic acid]
  4. (4)[figure: 1-bromocyclopentane-1-carbaldehyde (CHO\mathrm{CHO} and Br on the same ring carbon)]

Official answer

Option 1

NTA final key.

Chapter
Aldehydes, Ketones and Carboxylic Acids
Topic
Carboxylic Acids and Derivatives
Idea tested
Hell-Volhard-Zelinsky Reaction

Same idea in other shifts

Asked 4× in all
  1. 6 Apr 2023, Shift 1 · Q77Match List I with List II LIST I (Name of reaction) | LIST II (Reagent used) A. Hell-Volhard-Zelinsky reaction | I. NaOH+I2\mathrm{NaOH + I_2}…MediumMatch the list
  2. 30 Jun 2022, Shift 1 · Q74Consider the given chemical reaction [structure: a six-membered saturated carbon ring bearing a C(=O)OH group (carbonyl O drawn above the…EasyDiagram basedHas a figure
  3. 4 Aug 2021, Shift 1 · Q44Identify the reagent in the following reaction. CH3−CH2−C(=O)−OH→ReagentCH3−CH(X)−C(=O)−OH\mathrm{CH_3-CH_2-C(=O)-OH \xrightarrow{Reagent} CH_3-CH(X)-C(=O)-OH} (X = Cl, – Br)EasySingle correctHas 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.