THE VOLUMETRIC AND THERMOCHEMICAL PROPERTIES OF AQUEOUS-SOLUTIONS OF L-VALINE, L-LEUCINE, AND L-ISOLEUCINE AT 288.15-K, 298.15-K, 313.15-K,AND 328.15-K

Densities and volumetric heat capacities have been measured for aqueou s solutions of L-valine, L-leucine, and L-isoleucine at 288.15, 298.15 , 313.15, and 328.15 K. These data have been used to calculate apparen t molar volumes, V-2,V-phi, and apparent molar heat capacities, C-p,C- 2,C-phi, which in turn have been used to obtain standard state volumes , ($) over bar V-2(0), and standard state heat for capacities, ($) ove r bar C-p,2(0), each aqueous amino acid system. Helgeson, Kirkham, and Flowers equations, for neutral organics in water, have been used to m odel the calculated standard state volumes and heat capacities of the amino acids as a function of temperature at constant pressure. The res ults of our fitting procedures may be used to predict the behaviour of ($) over bar V-2(0) and ($) over bar C-p,2(0) for the selected amino acid systems outside of the temperature range utilised in this investi gation.