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JEE Main levelSingle correct optionDifficulty 2 of 3g3012

Which of the following carbocations is the most stable?

A $C X_{6} H X_{5} CH X_{2} X^{+}$
B $(CH X_{3}) X_{3} C X^{+}$
C $(CH X_{3}) X_{2} CH X^{+}$
D $(C X_{6} H X_{5}) X_{3} C X^{+}$ (triphenylmethyl cation)

Answer: D

Each phenyl ring delocalises the charge by resonance, and three rings are better than one. Resonance with three aryl groups outweighs the hyperconjugation of a tertiary alkyl cation, so trityl is the most stable (trityl salts can be isolated).

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