Nature of the Carbonyl Group 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