Partial Molar Volumes of some a-Aminocarboxylic Acids in Water

Abstract

Partial molar volumes of a number of α-aminocarboxylic acids in water at 25°C are measured. The results indicate that 4.33 ± 0.39 water molecules hydrate an α-amino acid. Contributions of the side chains or their constituent parts to the partial molar volumes are deduced. Volumes of proton ionization for α-amino acids with nitrogen-containing side chains are calculated and they indicate the absence of any significant electrostatic effects by terminal charged groups.