What is the hybridization of the indicated nitrogen atom?

• A. sp³ in this resonance contributor, but sp² in the other resonance contributor.
• B. sp²
• C. sp³
• D. sp

Answer: (B)

Verified step by step guidance

1. Identify the nitrogen atom in the structure and note its connectivity. The nitrogen is bonded to two carbon atoms and has a lone pair of electrons.
2. Consider the resonance structures of the molecule. The lone pair on the nitrogen can participate in resonance with the adjacent carbonyl group, forming a double bond between nitrogen and the carbonyl carbon.
3. In the resonance structure where the nitrogen forms a double bond, the nitrogen atom is involved in a pi bond, which requires p orbitals. This suggests sp2 hybridization.
4. In the original structure without resonance, the nitrogen is bonded to three groups (two carbons and a lone pair), which typically suggests sp3 hybridization.
5. Conclude that the nitrogen atom exhibits sp2 hybridization in the resonance structure where it participates in pi bonding, and sp3 hybridization in the structure where it does not participate in resonance.