JEE Chemistry · Hard

Chemical Bonding: Resonance MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

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ResonanceHardQuestion 600333

Question

The bond lengths in the carbonate ion CO₃²⁻ are all equal because:
  1. A
    Carbon has sp hybridisation
  2. B
    All three C−O bonds are equivalent by resonance
    Correct
  3. C
    CO₃²⁻ has three single bonds
  4. D
    Oxygen is more electronegative than carbon

Correct answer

All three C−O bonds are equivalent by resonance

Explanation

CO₃²⁻ has 3 equivalent resonance structures. The delocalised electrons make all C−O bonds identical with bond order = 4/3, intermediate between single and double bond.