Import Question JSON

$\text{Hint: Tertiary carbocation is more stable than primary benzylic carbocation}$ $\text{Explanation:}$ $\text{The stability of carbocation follow the order 3° >2° >1° >methyl. More the number of alkyl groups attached with the carbon atom carrying the positive charge greater would be the tendency to stabilise positive charge via inductive effect and hence more stable.}$ $\text{(1) Tertiary carbocation with 9 alpha-hydrogen and 9 hyperconjugation structures - This structure is more stable due to nine a-hydrogen and nine hyperconjugation structures.}$ $\text{(2) Secondary carbocation containing 6 alpha-hydrogen showing six hyperconjugation structures.}$ $\text{(3) Benzyl carbocation - Benzyl carbocation ion is stable due to the resonance effect.}$ $\text{(4) Primary carbocation less stable than all present here - The primary carbocation is highly unstable due to the strong -I effect of NO}_2\text{ group.}$ $\text{Here, tertiary carbocation is exceptionally highly stable because it can form 9 hyperconjugation structures. Thus, option 2 is the correct answer.}$ $\text{NB= It is an exception, generally resonance is more effective than hyperconjugation but here tertiary carbocation is more stable than primary benzylic carbocation.}$ $\text{The bond dissociation energy of a tertiary carbocation and a benzyl carbocation varies due to different factors such as resonance effects and steric hindrance. Generally, the bond dissociation energy of a tertiary carbocation is lower than that of a benzyl carbocation due to the stabilizing effects of hyperconjugation and electron delocalization in the tertiary carbocation.}$