Chemistry - GOC Question with Solution | TestHub

The stability of these carbanions depends directly on the resonance delocalization of the negative charge into the aromatic phenyl (Ph) rings.

Carbanion Ph₃C⁻ (I) is bonded to three phenyl rings, allowing the negative charge to disperse extensively across all three rings, creating the maximum number of resonance structures.

Carbanion Ph₂CH⁻ (II) has two phenyl rings for delocalization, while PhCH₂⁻ (III) is stabilized by only one phenyl ring.

Since a greater number of contributing resonance structures increases stability, the overall decreasing order of stability is I > II > III.