When a Carbonyl Is Part of a Conjugated π-Network, the C

Multiple Choice

When a carbonyl is part of a conjugated π-network, the C O stretch ________.

A) has a higher frequency than in a nonconjugated system
B) has a lower frequency than in a nonconjugated system
C) always occurs at 1710 cm^-1
D) occurs around 2700 cm^-1
E) cannot be distinguished from the C O stretch in a nonconjugated system