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Saturday, 31 October

JEE Main 2021 · ChemistryNumerical answerNumerical valueMediumMulti-step

JEE Main 25 July 2021, Shift 2, Chemistry Q60

Question 60 of 90 in this shift, Chemistry question 30 of 30, Section B.

[reaction scheme: drawn structure] + Br2\mathrm{Br_2} →CCl4\xrightarrow{\mathrm{CCl_4}} Product "P" Consider the above chemical reaction. The total number of stereoisomers possible for Product 'P' is ________.

The figure, in words

Drawn alkene: a double bond drawn vertically; top carbon bears H3C (upper left) and H (upper right); bottom carbon bears H3C (lower left) and H (lower right). Reaction arrow with CCl4 above, + Br2 before the arrow, Product "P" after.

Official answer

2

NTA final key.

Chapter
Hydrocarbons
Topic
Alkenes and Alkynes
Idea tested
Halogenation Anti-Addition Stereochemistry

Same topic in other shifts

All Alkenes and Alkynes questions
  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. 4 Apr 2026, Shift 2 · Q64Compound (X) is subjected to the sequence of reactions as shown above. Molar mass of the major product (Y) formed is ________…MediumDiagram basedHas a figure
  3. 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
  4. 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
  5. 6 Apr 2026, Shift 2 · Q65An optically active alkyl bromide C4H9Br\mathrm{C_4H_9Br}, reacts with ethanolic KOH to form major compound [A] which reacts with bromine to…MediumSingle correct
  6. 2 Apr 2025, Shift 1 · Q66An optically active alkyl halide C4H9Br\mathrm{C_4H_9Br} [A] reacts with hot KOH dissolved in ethanol and forms alkene [B] as major product…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.