Which of the following is the most stable carbocation?

Question

Question

This question was previously asked in

AIIMS BSc NURSING 2023 Memory-Based Paper

Answer 1

CONCEPT:

Carbocation Stability

Carbocations are positively charged carbon species which are intermediates in many organic reactions.
The stability of carbocations depends on the number of alkyl groups attached to the positively charged carbon atom and the ability of adjacent atoms or groups to donate electron density to the positively charged carbon.
Alkyl groups stabilize carbocations through hyperconjugation and inductive effects, while resonance and other stabilizing interactions can also play significant roles.

EXPLANATION:

CH3CH2CH2+ is a primary carbocation.
CH3CH+CH3 is a secondary carbocation.
(CH3)3C+ is a tertiary carbocation.
CH3CH2+ is an ethyl carbocation, which is also a primary carbocation.
The stability order of carbocations is typically: tertiary > secondary > primary > methyl.
This is because tertiary carbocations have three alkyl groups that can donate electron density through hyperconjugation and inductive effects, making them more stable.

Therefore, the most stable carbocation among the given options is (CH3)3C+ (tertiary carbocation).