Solvation thermodynamics of four amino acids in electrolytic solutions of sodium and potassium iodide salts at 298.15 K

Abstract

The solubility and thermodynamics of solvation due to solute–solvent interactions of glycine, DL-alanine, DL-serine, and DL-valine were determined in this study. Mainly, the transfer of Gibbs free energies from aqueous to aqueous sodium and potassium iodide salt solutions was considered, which were calculated by direct experimental solubility data and via theoretical calculations. The equilibrium solubilities were measured at 298.15 K using simple “formol titration”. Various important physicochemical factors like enthalpy of solvation, molar volume, molar mass, molar density, etc., in aqueous electrolyte solutions were calculated at standard temperature. The thermodynamic parameters were explained to conclude about the virtual stability of the zwitterionic solutes in aqueous salt mixtures. The factors that are associated with solubility were also explained and correlated with physical and thermodynamic point of view.