3300 and 3385 cm-1 (both weak) and no band between 1600 and 1850 cm-1

A compound has infrared absorptions at the following frequencies: 3300 and 3385 cm-1 (both weak) and no band between 1600 and 1850 cm-1 Suggest the likely functional group that may be preser

Answer

There is no C=O in this compound because the IR signal for C=O is ~1700
So the following can’t be present: ester, ketone, carboxyl group, aldehyde, primary amide, secondary amide, and tertiary amide
There is no -OH group because the IR signal for -OH is broad at ~3400 So the following can’t be present: alcohol
Now the choices, we are left with are: primary amine, secondary amine, and tertiary amine. Note that the primary amine results in 2 bands, secondary amine results in only 1 band, and teritary amine results in no bands near ~3300. This represents the N-H stretching.

The likely functional group present is primary amine