JEE Main · 2023 · Shift-IeasyHC-010

In the following reaction, 'X' is:

Hydrocarbons · Class 11 · JEE Main Previous Year Question

Question

In the following reaction, 'X' is:

image

Options
  1. a

    \ceCH3(CH2)4CH2Cl\ce{CH3(CH2)_4CH2Cl}

  2. b

    \ceClCH2(CH2)4CH2Cl\ce{Cl-CH2-(CH2)_4-CH2-Cl}

  3. c

    2-methylpentane (branched alkane)

  4. d

    Cyclohexane

Correct Answerc

2-methylpentane (branched alkane)

Detailed Solution

When heated in the presence of \ceHCl\ce{HCl} gas and anhydrous \ceAlCl3\ce{AlCl3}, n-alkanes are isomerized to branched chain alkanes. The primary product has one side chain of methyl. The reaction takes place as: image Option (c) — 2-methylpentane (the branched alkane shown in the structure) is correct answer.

Key Points to Remember:

  • \ceAlCl3/HCl\ce{AlCl3/HCl} isomerizes n-alkanes to branched alkanes
  • This is the basis of catalytic reforming in petroleum refining
  • The major product is the singly branched isomer (not the most branched)

Practice this question with progress tracking

Want timed practice with adaptive difficulty? Solve this question (and hundreds more from Hydrocarbons) inside The Crucible, our adaptive practice platform.

In the following reaction, 'X' is: (JEE Main 2023) | Canvas Classes