Question

Given below are two statements:
Statement I: $CH_3)_3C^+$ is more stable than $CH_3CH_2^+$ as nine hyperconjugation interactions are possible in $(CH_3)_3C^+$.
Statement II: $CH_3^+$ is less stable than $(CH_3)_3C^+$ as only three hyperconjugation interactions are possible in $CH_3^+$.
In the light of the above statements, choose the correct answer...

• A. Statement I is false but Statement II is true
• B. Both Statement I and Statement II are false
• C. Both Statement I and Statement II are true
• D. Statement I is true but Statement II is false

Hint:

Hyperconjugation involves delocalization of $\sigma$-electrons of C-H bond of an alkyl group directly attached to an atom with an unshared p orbital. Count $\alpha$-hydrogens.

Answer 1

The Correct Option is D

Statement I: tert-butyl cation ($9 \alpha$-Hydrogens) is indeed more stable than ethyl cation ($3 \alpha$-Hydrogens) due to hyperconjugation. This statement is True.
Statement II: Methyl cation ($CH_3^+$) has 0 $\alpha$-Hydrogens, so 0 hyperconjugation structures are possible. The statement claims "only three" are possible, which is incorrect. Thus, Statement II is False.