Question

what is the stretching frequency (in cm⁻¹) of the following carbonyl?
o
h
n
h
1685
1745
1715

Explanation:

Step1: Identify the carbonyl type

The given compound is a primary amide.

Step2: Recall amide carbonyl stretching frequency range

Primary amide carbonyls typically have stretching frequencies around 1680 - 1640 cm⁻¹ due to resonance and hydrogen - bonding effects.

Answer:

1685