Question

Given below are two statements:
Statement I: On the basis of inductive effect, the order of stability of alkyl carbanions is \(CH_3^->CH_3-CH_2^->(CH_3)_2CH^->(CH_3)_3C^-\).
Statement II: Allyl and benzyl carbanions are more stabilised by inductive effect and not by resonance effect.

• A. Both Statement I and Statement II are correct
• B. Both Statement I and Statement II are incorrect
• C. Statement I is correct but Statement II is incorrect
• D. Statement I is incorrect but Statement II is correct

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question tests the factors affecting the stability of carbanions, specifically inductive and resonance effects.
Step 2: Detailed Explanation:
Statement I: Alkyl groups have a \(+I\) (electron-donating) effect. In a carbanion, the carbon already has a negative charge. Electron donation from alkyl groups increases the electron density further, making the carbanion less stable. Therefore, the more alkyl groups attached, the less stable the carbanion is. The order \(CH_3^- (methyl)>1^\circ>2^\circ>3^\circ\) is Correct.
Statement II: Allyl (\(CH_2=CH-CH_2^-\)) and benzyl (\(C_6H_5-CH_2^-\)) carbanions are primarily stabilized by the delocalization of the negative charge through \(\pi\)-systems, which is the resonance effect. Inductive effect plays a minor role compared to resonance. The statement says they are stabilized by inductive and *not* resonance. Incorrect.
Step 3: Final Answer:
Statement I is correct but Statement II is incorrect.