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Friday, 9 October

JEE Main 2025 · ChemistryMultiple choiceOtherMediumMulti-step

JEE Main 7 April 2025, Shift 2, Chemistry Q66

Question 66 of 75 in this shift, Chemistry question 16 of 25, Section A.

The number of optically active products obtained from the complete ozonolysis of the given compound is : H3C−CH=CH−C(CH3)(H)−CH=CH−C(H)(CH3)−CH=CH−CH3\mathrm{H_3C-CH=CH-C(CH_3)(H)-CH=CH-C(H)(CH_3)-CH=CH-CH_3} (stereocentres drawn with wedge/hash bonds)

The figure, in words

Skeletal chain H3C-CH=CH-C*-CH=CH-C*-CH=CH-CH3 with two stereocentres: the first C* has CH3 on a wedge (up) and H on a hash (down); the second C* has H on a wedge (up) and CH3 on a hash (down).
  1. (1)0Official answer
  2. (2)1
  3. (3)2
  4. (4)4

Official answer

Option 1

NTA final key.

Chapter
Aldehydes, Ketones and Carboxylic Acids
Topic
Alkenes and Alkynes
Idea tested
Reductive Ozonolysis Products

Same idea in other shifts

Asked 8× in all
  1. 4 Apr 2026, Shift 1 · Q64An alkene (X) on ozonolysis followed by reduction gives following products. H−CHO\mathrm{H-CHO} (2 moles), OHC−CO−CHO\mathrm{OHC-CO-CHO}…HardDiagram basedHas a figure
  2. 5 Apr 2026, Shift 1 · Q64"P" is a hydrocarbon of molecular formula:- C8H14\mathrm{C_8H_{14}}. On ozonolysis, "P" forms "Q". "Q" on treatment with alkali under reflux…HardDiagram basedHas a figure
  3. 3 Apr 2025, Shift 1 · Q65Which compound would give 3-methyl-6-oxoheptanal upon ozonolysis?MediumDiagram basedHas a figure
  4. 7 Apr 2025, Shift 1 · Q67Given below are two statements: Statement I: Ozonolysis followed by treatment with Zn, H2O\mathrm{H_2O} of cis-2-butene gives ethanal.…MediumTwo statements
  5. 29 Jan 2024, Shift 1 · Q89[figure: trans-2-butene drawn as CH3_3 and H on the left carbon, H and CH3_3 on the right carbon (CH3_3 top-left, H bottom-left, H…EasyNumerical valueHas a figure
  6. 25 Jul 2022, Shift 1 · Q73A compound 'A' on reaction with 'X' and 'Y' produces the same major product but different by product 'a' and 'b'. Oxidation of 'a' gives a…MediumSingle correctHas a figure
  7. 25 Jul 2021, Shift 1 · Q42An Organic compound 'A' C4H8\mathrm{C_4H_8} on treatment with KMnO4/H+\mathrm{KMnO_4/H^+} yields compound 'B' C3H6O\mathrm{C_3H_6O}. Compound 'A'…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 42 of the 174 JEE Main shifts held from 2017 to 2026.