JEE Main · 2020 · Shift-IIeasyBOND-119

Arrange the following bonds according to their average bond energies in descending order: C–Cl, C–Br, C–F, C–I

Chemical Bonding · Class 11 · JEE Main Previous Year Question

Question

Arrange the following bonds according to their average bond energies in descending order: C–Cl, C–Br, C–F, C–I

Options
  1. a

    C–F > C–Cl > C–Br > C–I

  2. b

    C–Br > C–I > C–Cl > C–F

  3. c

    C–I > C–Br > C–Cl > C–F

  4. d

    C–Cl > C–Br > C–I > C–F

Correct Answera

C–F > C–Cl > C–Br > C–I

Detailed Solution

🧠 Bond energy for C–X bonds: shorter bonds are stronger. Bond length increases with the size of the halogen: C–F < C–Cl < C–Br < C–I. Therefore bond energy decreases in the same order.

| Bond | Approximate energy (kJ/mol) | Bond length (pm) | |---|---|---| | C–F | ~485 | ~135 | | C–Cl | ~330 | ~177 | | C–Br | ~285 | ~194 | | C–I | ~213 | ~214 |

Decreasing bond energy: C–F > C–Cl > C–Br > C–I

Answer: (a) C–F > C–Cl > C–Br > C–I\boxed{\text{Answer: (a) C–F > C–Cl > C–Br > C–I}}

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Arrange the following bonds according to their average bond energies in descending order: C–Cl,… (JEE Main 2020) | Canvas Classes