Chemistry - CHEMICAL BONDING Question with Solution | TestHub

Question Explanation: Identify the molecule with perfectly equal $\mathrm{C}-\mathrm{O}$ bond lengths.

Concept:

Resonance and Symmetry.

Solution:

Bond lengths become equal when all bonds share identical double-bond character through resonance or cumulative systems.

Carbon suboxide ( $\mathrm{O}=\mathrm{C}=\mathrm{C}=\mathrm{C}=\mathrm{O}$ ) is a linear molecule with a system of cumulative double bonds. Both terminal $\mathrm{C}=\mathrm{O}$ bonds are identical double bonds by symmetry.

In the other options, resonance involves non-equivalent structures (like hydroxyl vs carbonyl) which prevents exact equality.

Final Answer: Option (D)