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Saturday, 31 October

JEE Main 2024 · ChemistryMultiple choiceOtherEasyMulti-step

JEE Main 4 April 2024, Shift 1, Chemistry Q77

Question 77 of 90 in this shift, Chemistry question 17 of 30, Section A.

Identify the correct set of reagents or reaction conditions 'X' and 'Y' in the following set of transformation. CH3−CH2−CH2−Br→′X′Product→′Y′CH3−CH−CH3\mathrm{CH_3-CH_2-CH_2-Br} \xrightarrow{'X'} \mathrm{Product} \xrightarrow{'Y'} \mathrm{CH_3-CH-CH_3} (with Br on the middle carbon)
  1. (1)X = dil.aq. NaOH, 20°C, Y = HBr/acetic acid
  2. (2)X = conc.alc. NaOH, 80°C, Y = HBr/acetic acidOfficial answer
  3. (3)X = dil.aq. NaOH, 20°C, Y = Br2/CHCl3\mathrm{Br_2/CHCl_3}
  4. (4)X = conc.alc. NaOH, 80°C, Y = Br2/CHCl3\mathrm{Br_2/CHCl_3}

Official answer

Option 2

NTA final key.

Chapter
Haloalkanes and Haloarenes
Topic
Alkenes and Alkynes
Idea tested
Markovnikov's Rule Application

Same idea in other shifts

Asked 13× in all
  1. 6 Apr 2026, Shift 1 · Q66Given below are two statements: Statement I: 3-phenylpropene reacts with HBr and gives secondary alkyl bromide having a chiral carbon atom…MediumTwo statements
  2. 4 Apr 2025, Shift 2 · Q65Consider the following molecule (X). The structure of X is [figure: tricyclic fused polycyclic hydrocarbon (X) containing a cyclopentene…HardDiagram basedHas a figure
  3. 31 Jan 2024, Shift 1 · Q76The product (C) in the below mentioned reaction is :…EasySingle correct
  4. 31 Jan 2024, Shift 2 · Q75Major product of the following reaction is -HardDiagram basedHas a figure
  5. 25 Jul 2022, Shift 2 · Q73Major product of the following reaction is [figure: skeletal drawing, left to right: a C=C double bond at the left end whose inner carbon…MediumDiagram basedHas a figure
  6. 24 Jun 2022, Shift 1 · Q90The major product 'A' of the following given reaction has ______ sp2sp^2 hybridized carbon atoms. 2,7-Dimethyl-2,6-octadiene…HardNumerical value
  7. 25 Jun 2022, Shift 1 · Q73The product formed in the following reaction. [figure: (CH3)2C=CH2\mathrm{(CH_3)_2C{=}CH_2} drawn with two CH3\mathrm{CH_3} on the left carbon and…MediumDiagram basedHas a figure
  8. 28 Jun 2022, Shift 1 · Q73The major product (P) in the reaction [reaction drawn: Ph at left, zigzag chain of three carbons with a C=C double bond between the first…MediumDiagram basedHas 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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.