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Saturday, 31 October

JEE Main 2020 · ChemistryMultiple choiceSingle correctHardMulti-step

JEE Main 9 January 2020, Shift 2, Chemistry Q43

Question 43 of 75 in this shift, Chemistry question 18 of 25, Section A.

Which of the following reactions will not produce a racemic product ?

The figure, in words

Option 2 is a drawn structure: a cyclohexene ring with CH3 at one ring carbon and CH3 on the double-bond carbon, reacting with HCl.
  1. (1)CH3CH2CH=CH2→HBr\mathrm{CH_3CH_2CH=CH_2} \xrightarrow{HBr}
  2. (2)[figure: 1,3-dimethylcyclohexene (ring double bond at the carbon bearing CH3, a second CH3 on the ring) →HCl\xrightarrow{HCl}]
  3. (3)CH3−CH(CH3)−CH=CH2→HCl\mathrm{CH_3-CH(CH_3)-CH=CH_2} \xrightarrow{HCl} (the carbon bearing CH3 and H is drawn vertically)Official answer
  4. (4)CH3−C(=O)−CH2CH3→HCN\mathrm{CH_3-C(=O)-CH_2CH_3} \xrightarrow{HCN}

Official answer

Option 3

NTA final key (Jan 2020).

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. 4 Apr 2024, Shift 1 · Q77Identify the correct set of reagents or reaction conditions 'X' and 'Y' in the following set of transformation.…EasyOther
  4. 31 Jan 2024, Shift 1 · Q76The product (C) in the below mentioned reaction is :…EasySingle correct
  5. 31 Jan 2024, Shift 2 · Q75Major product of the following reaction is -HardDiagram basedHas a figure
  6. 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
  7. 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
  8. 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

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.