Question

In compound (X), hyperconjugation is present and in (Y), resonance effect is present. What are X and Y, respectively?

• A. Toluene, prop-2-en-1-ol
• B. Aniline, 2-propenal
• C. Toluene, nitrobenzene
• D. 1-Bromopropane, phenol

Hint:

Hyperconjugation: C-H next to $\pi$ bond. Resonance: Delocalization of $\pi$ electrons or lone pairs.

Answer 1

The Correct Option is C

Hyperconjugation: Occurs when there is a C-H bond adjacent to a pi bond (or an empty p orbital). Toluene exhibits hyperconjugation due to the C-H bonds on the methyl group adjacent to the benzene ring.
Resonance effect: Occurs when there is delocalization of pi electrons or lone pairs through the molecule. Nitrobenzene exhibits a resonance effect due to the interaction between the lone pairs on oxygen (in the nitro group) and the pi electrons of the benzene ring.