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Saturday, 31 October

JEE Main 2021 · ChemistryMultiple choiceTwo statementsMediumConceptual

JEE Main 27 August 2021, Shift 2, Chemistry Q45

Question 45 of 90 in this shift, Chemistry question 15 of 30, Section A.

Given below are two statements : Statement I : Ethyl pent-4-yn-oate on reaction with CH3MgBr\mathrm{CH_3MgBr} gives a 3∘3^\circ-alcohol. Statement II : In this reaction one mole of ethyl pent-4-yn-oate utilizes two moles of CH3MgBr\mathrm{CH_3MgBr}. In the light of the above statements, choose the most appropriate answer from the options given below :
  1. (1)Both Statement I and Statement II are true
  2. (2)Both Statement I and Statement II are false
  3. (3)Statement I is true but Statement II is falseOfficial answer
  4. (4)Statement I is false but Statement II is true

Official answer

Option 3

NTA final key.

Chapter
Aldehydes, Ketones and Carboxylic Acids
Topic
Carboxylic Acids and Derivatives
Idea tested
Reaction of Esters with Grignard Reagents

Same idea in other shifts

Asked 4× in all
  1. 9 Apr 2024, Shift 2 · Q79Major product of the following reaction is [figure: 4-cyanophenyl methyl ester, i.e. benzene ring with CN at one para position and…MediumSingle correctHas a figure
  2. 22 Jul 2021, Shift 2 · Q46Which one of the following compounds will provide a tertiary alcohol on reaction with excess of CH3MgBr\mathrm{CH_3MgBr} followed by hydrolysis ?MediumDiagram basedHas a figure
  3. 2 Apr 2017 (offline) · Q59The correct sequence of reagents for the following conversion will be : [reaction: 4-formylcyclohexanone (ring bearing C=O at the top and…HardSingle 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. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.