Nature of the Carbonyl Group R R R R Name Nomenclature Dipole moment -R or-Ar H aldehyde -al 2.7D -R or-Ar -R or-Ar ketone -one 2.9D -R or -Ar -OH carboxylic acid -oic acid 1.7D -R or-Ar -OR" ester -oate 1.7D -R or -Ar -NH2 amide -amide 3.8D -R or-Ar X acid halide -oyl halide 2.7D