Question

Allyl carbocation is primary carbocation yet it is more stable than tertiary butyl carbocation

Answer 1

Allylic carbocations are resonance stabilized whereas tertiary alkyl groups are stabilized by hyperconjugation (and inductive effect). The hyperconjugation (and inductive effect), in general, is quite weaker than resonance (and hyperconjugation effect). The only exceptions to the previous statement I am aware of are halogens (inductive effect is stronger than resonance).

Answer 2

Answer:

just wanted to let you know that I will follow up