The number of no bond resonance structures possible for but-1-ene and a `3^(@)` carbocation having methyl, ethyl and isobutyl groups on cationic carbon respectively are

Options

A. 3, 7
B. 4, 6
C. 2, 7
D. 5, 6

Answer

C

Explanation

No bond resonance (hyperconjugation) depends on number of `alpha - H`
`CH_3 - CH_2 - CH = CH_2`
But-1-ene contains `alpha - H` . Therefore, it gives 2 no bond resonating structures

`3^@` carbocation has `7alpha-H`
Thus, it forms 7 no bond resonating structures.