Statement I: On the basis of inductive effect, the order of stability of alkyl carbanions is:

CH₃^- > CH₃CH₂^- > (CH₃)₂CH^- > (CH₃)₃C^-

Statement II: Allyl and benzyl carbanions are stabilized by inductive effect and not by resonance.

Choose the correct answer.

• (1) Both Statement I and Statement II are correct.
• (2) Both Statement I and Statement II are incorrect.
• (3) Statement I is correct but Statement II is incorrect.
• (4) Statement I is incorrect but Statement II is correct.

A carbanion is a negatively charged carbon species containing a lone pair of electrons. The stability of carbanions depends on factors such as inductive effect, resonance, hybridization, and aromaticity.

Let us first examine Statement I.

Alkyl groups show a +I (electron-releasing) effect. Since a carbanion already carries a negative charge, electron-releasing alkyl groups increase electron density and destabilize the carbanion.

Therefore, increasing alkyl substitution decreases stability:

CH₃^- > 1° > 2° > 3°

CH₃^- > CH₃CH₂^- > (CH₃)₂CH^- > (CH₃)₃C^-

Hence Statement I is correct.

Now consider Statement II.

Allyl and benzyl carbanions are highly stable because the negative charge is delocalized through resonance. The charge can spread over several atoms instead of remaining localized on one carbon atom.

For example:

• Allyl carbanion distributes negative charge over three carbon atoms.
• Benzyl carbanion distributes negative charge throughout the aromatic ring.

This resonance stabilization is the primary reason for their extra stability. Inductive effect contributes very little compared with resonance.

Therefore, the statement saying they are stabilized by inductive effect and not by resonance is incorrect.

Thus:

• Statement I = Correct
• Statement II = Incorrect

Correct Option: (3)