Partial molar heat capacities and volumes of transfer of some saccharides from water to aqueous sodium chloride solutions at T=298.15 K

Abstract

Partial molar heat capacities (C°_p,2,m) and volumes (V°_2,m) of seven monosaccharides, namely, D(-)-ribose, D(-)-arabinose, D(+)-xylose, D(+)-glucose, D(+)-mannose, D(+)-galactose, and D(- )-fructose; five disaccharides, namely, sucrose, D(+)-cellobiose, D(+)-maltose monohydrate, D(+)-lactose monohydrate, D(+)-trehalose dihydrate, and one trisaccharide, D(+)-raffinose pentahydrate, have been determined in NaCl(aq), m = (1.0, 2.0, and 3.0) mol·kg^-1 at T=298.15 K from volumic heat capacity and density measurements employing a Picker flow microcalorimeter and a vibrating-tube densimeter, respectively. These data were combined with the earlier reported C°_p,2,m and V°_2,m values in water to calculate the corresponding partial molar properties of transfer (Δ_trC°_p,2,m and Δ_trV°_2,m) from water to aqueous sodium chloride solutions at infinite dilution. These transfer parameters are positive, and the values increase with the concentration of sodium chloride for all the saccharides. Transfer parameters have been discussed in terms of solute-cosolute interactions on the basis of a cosphere overlap model. Pair and higher-order interaction coefficients have also been calculated from transfer parameters.