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Saturday, 31 October

JEE Main 2021 · ChemistryMultiple choiceDiagram basedEasyApplication

JEE Main 3 August 2021, Shift 1, Chemistry Q43

Question 43 of 90 in this shift, Chemistry question 13 of 30, Section A.

Find out the major product of the following reaction

The figure, in words

Reactant drawn in skeletal form: a chain with a terminal =CH2 double bond at a carbon carrying one vertical line substituent and one ethyl-type chain; reagents '1) Hg OAc 2, H2O' and '2) NaBH4 / H3O+' (printed as 'Hg OAc 2' with the 2 as a subscript) over an arrow, then '?'.
  1. (1)[figure: skeletal zigzag chain with a vertical single-bond line going down from one inner vertex, and OH on the last vertex at the right end]
  2. (2)[figure: skeletal structure in which one vertex has four bonds drawn: two chain lines, a vertical line down, and OH to the lower right]Official answer
  3. (3)[figure: skeletal zigzag chain with a vertical single-bond line going down from the middle vertex; no OH and no double bond]
  4. (4)[figure: skeletal chain with a C=C double bond between the first two vertices at the left; the second vertex also has a line going up-right and a vertical line going down]

Official answer

Option 2

NTA final key.

Chapter
Alcohols, Phenols and Ethers
Topic
Alcohols and Phenols
Idea tested
Oxymercuration-Demercuration Regioselectivity

Same topic in other shifts

All Alcohols and Phenols questions
  1. 4 Apr 2026, Shift 1 · Q70Identify the colour of compound 'X' in the sequence of the reaction.MediumDiagram basedHas a figure
  2. 4 Apr 2026, Shift 2 · Q70Match the LIST-I with LIST-II List-I (Compound): A. [figure: cyclohexane ring bearing OH] B. [figure: cyclohexane ring bearing NH2] C.…MediumMatch the listHas a figure
  3. 5 Apr 2026, Shift 1 · Q67Consider compounds A, B and C with following structural formulae A = CH3−CH2−CH2−CH2−CH2−OH\mathrm{CH_3-CH_2-CH_2-CH_2-CH_2-OH} B =…EasyOtherHas a figure
  4. 5 Apr 2026, Shift 1 · Q73One mole of phenol is treated with dilute HNO3\mathrm{HNO_3} at 298 K to give a mixture of products. The mixture is separated by steam…MediumNumerical value
  5. 6 Apr 2026, Shift 1 · Q734.7 g of phenol is heated with Zn to give product X. If this reaction goes to 60% completion then the number of moles of compound X formed…EasyNumerical value
  6. 3 Apr 2025, Shift 1 · Q68Number of molecules from below which cannot give iodoform reaction is: Ethanol, Isopropyl alcohol, Bromoacetone, 2−-Butanol,…MediumSingle correct

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.