Viscometric and Thermodynamic Studies of D-Galactose and D-Maltose in Sodium Sulfide Solution (0.25M) at Different Temperatures

Abstract

Densities ρ and Viscosities ŋ of D-Galactose and D-Maltose (0.05-0.4)M in aqueous solution (0.25) M of Na₂S at 298.15, 303.15 and 308.15K have been measured. From these experimental data, apparent molal Volume Limiting Apparent Molal Volume ( ) ,The slope ( ) , Jones-Dole coefficient A and B, The free energy of activation of viscous flow (ΔG^*), The enthalpies (ΔH^*) and Entropies (ΔS^*)  were calculated, A values compatible with the ( ) values of weak solute-solute interaction while B came with positive and high,which indicating the strength of the reciprocal interaction type solute-solvent. This serves to strengthen of the structure of solvent. due to hydrophobic hydration and hydrogen bonding between solute and water , sodium sulfide molecules and on the other hand the water molecules rearranges toward formation of a local cage like (clathrates) structure surrounding each solute molecule