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Saturday, 31 October

JEE Main 2025 · ChemistryMultiple choiceDiagram basedHardApplication

JEE Main 4 April 2025, Shift 2, Chemistry Q65

Question 65 of 75 in this shift, Chemistry question 15 of 25, Section A.

Consider the following molecule (X). The structure of X is [figure: tricyclic fused polycyclic hydrocarbon (X) containing a cyclopentene ring with a C=C, a six-membered ring with a C=C, and a lower five-membered ring with an exocyclic-type C=C at the ring fusion] The major product formed when the given molecule (X) is treated with HBr (1 eq) is :

The figure, in words

Structure X: fused tricyclic hydrocarbon with three C=C bonds (one in the upper cyclopentene ring, one in the six-membered ring, one at the lower five-membered ring); options show HBr addition products.
  1. (1)[figure: tricyclic structure with Br on the tertiary ring-fusion carbon of the lower five-membered ring; both other C=C bonds retained]Official answer
  2. (2)[figure: tricyclic structure with Br and H on a carbon of the six-membered ring; lower C=C and cyclopentene C=C retained]
  3. (3)[figure: tricyclic structure with Br and H on a CH carbon of the upper five-membered ring; six-membered ring C=C and lower C=C retained]
  4. (4)[figure: tricyclic structure with Br and H on a CH carbon of the lower-left five-membered ring; six-membered ring C=C and lower C=C retained]

Official answer

Option 1

NTA final key.

Chapter
Haloalkanes and Haloarenes
Topic
Alkenes and Alkynes
Idea tested
Markovnikov's Rule Application

Same idea in other shifts

Asked 13× in all
  1. 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
  2. 4 Apr 2024, Shift 1 · Q77Identify the correct set of reagents or reaction conditions 'X' and 'Y' in the following set of transformation.…EasyOther
  3. 31 Jan 2024, Shift 1 · Q76The product (C) in the below mentioned reaction is :…EasySingle correct
  4. 31 Jan 2024, Shift 2 · Q75Major product of the following reaction is -HardDiagram basedHas a figure
  5. 25 Jul 2022, Shift 2 · Q73Major product of the following reaction is [figure: skeletal drawing, left to right: a C=C double bond at the left end whose inner carbon…MediumDiagram basedHas a figure
  6. 24 Jun 2022, Shift 1 · Q90The major product 'A' of the following given reaction has ______ sp2sp^2 hybridized carbon atoms. 2,7-Dimethyl-2,6-octadiene…HardNumerical value
  7. 25 Jun 2022, Shift 1 · Q73The product formed in the following reaction. [figure: (CH3)2C=CH2\mathrm{(CH_3)_2C{=}CH_2} drawn with two CH3\mathrm{CH_3} on the left carbon and…MediumDiagram basedHas a figure
  8. 28 Jun 2022, Shift 1 · Q73The major product (P) in the reaction [reaction drawn: Ph at left, zigzag chain of three carbons with a C=C double bond between the first…MediumDiagram basedHas 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. 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.