Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The standard partial molar volumes, V 2 at infinite dilution of eight monosaccharides [D(+)-xylose, D( )- arabinose, D( )-ribose, L( )-sorbose, D( )-fructose, D(+)-galactose, D(+)-glucose, and D(+)-mannose], six disaccharides [D(+)-cellobiose, sucrose, D(+)-melibiose, D(+)-lactose monohydrate, D(+)-trehalose dihydrate, and D(+)-maltose monohydrate] and two trisaccharides [D(+)-melizitose and D(+)-raffinose pentahydrate] (molalities of saccharides range from (0.03 to 0.12) mol kg 1) have been determined in water and in (0.5, 1.0, 2.0, and 3.0) mol kg 1 aqueous sodium acetate solutions at temperatures, T = (288.15, 298.15, 308.15, and 318.15) K from density measurements using a vibrating-tube digital densimeter. From these results, corresponding standard partial molar volumes of transfer, DtV 2 have been determined for the transfer of various saccharides from water to aqueous solutions of sodium acetate. Positive values of DtV 2 were obtained for most of the saccharides, whose magnitude increase with the concentration of sodium acetate as well as temperature. However, negative DtV 2 values were observed for L( )-sorbose, D( )-fructose and D(+)-xylose at lower concentrations of co-solute. The negative magnitude of DtV 2 values decrease with rise of temperature from (288.15 to 318.15) K. Pair and higher order volumetric interaction coefficients have been determined by using McMillan Mayer theory. Partial molar expansion coefficients, o@V 2=@TPp and the second derivatives o@2V 2=@T2Pp have also been estimated. These parameters have been utilized to understand various mixing effects in aqueous solutions due to the interactions between solute (saccharide) and co-solute (sodium acetate).