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Friday, 9 October

JEE Main 2023 · ChemistryNumerical answerNumerical valueMediumApplication

JEE Main 11 April 2023, Shift 1, Chemistry Q90

Question 90 of 90 in this shift, Chemistry question 30 of 30, Section B.

[figure: 4-hydroxybutanal, OHC−CH2CH2CH2−OH\mathrm{OHC{-}CH_2CH_2CH_2{-}OH} (y mole)] →H3O+x mol of MeMgBr\xrightarrow[\mathrm{H_3O^+}]{x\ \text{mol of MeMgBr}} [figure: CH3CH(OH)CH2CH2CH2OH\mathrm{CH_3CH(OH)CH_2CH_2CH_2OH}] The ratio x/y on completion of the above reaction is ___________.

The figure, in words

Hydroxy aldehyde (y mole) with x mol MeMgBr then H3O+ gives the diol with Me added at the carbonyl carbon.

Official answer

2

NTA final key.

Chapter
Alcohols, Phenols and Ethers
Topic
Alcohols and Phenols
Idea tested
Grignard Synthesis of Alcohols

Same idea in other shifts

Asked 2× in all
  1. 9 Jan 2020, Shift 2 · Q50Consider the following reactions A →(ii) H3O+(i) CH3MgBr\xrightarrow[\text{(ii) } H_3O^+]{\text{(i) } CH_3MgBr} B →573 KCu\xrightarrow[573\text{ K}]{Cu}…MediumNumerical value

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 42 of the 174 JEE Main shifts held from 2017 to 2026.