Activity coefficients and conductivities of calcium nitrate in glucose/galactose–water mixtures at 298.15 K

Activity coefficients, Gibbs energy interaction parameters ( g ES), salting constants ( k S), limiting molar conductivities ( Λ 0), and Walden products ( Λ 0 η) for the calcium nitrate−monosaccharide ( d-glucose and d-galactose)–water systems were determined from electrical potential and conductance measurements. Results show that both the g ES and Λ 0 η values for saccharide−calcium nitrate–water systems are in the order: d-glucose > d-galactose. This can be ascribed to the fact that the interactions of Ca 2+ with d-galactose are stronger than those of the ions with d-glucose. d-Glucose is salted-out whereas d-galactose is salted-in by calcium nitrate in water, which results from the difference in stereo-structures of the saccharide molecules (axial hydroxyl, a-OH-4 and equatorial hydroxyl, e-OH-4).