Partial molar heat capacities and volumes of some mono-, di- and tri-saccharides in water at 298.15, 308.15 and 318.15 K

Partial molar heat capacities (<(C)over bar (0)(p,2)>) and partial molar volumes (<(V)over bar (0)(2)>) of seven monosaccharides [D(-)-ribose, D(-)-arabinose, D(+)-xylose, D(+)-glucose, D(+)-mannose, D(+)-galactose and D(-)-fructose], seven disaccharides [sucrose, D(+)-cellobiose, lactulose, D(+)-melibiose hemihydrate, D(+)-maltose monohydrate, D(+)-lactose monohydrate, D(+)-trehalose dihydrate] and one trisaccharide [D(+)-raffinose pentahydrate] have been determined at 298.15, 308.15 and 318.15 K using a Picker flow microcalorimeter and a vibrating-tube densimeter respectively. From these data partial molar expansion coefficients (partial derivative<(V)over bar (0)(2)>/partial derivative T)(p), isothermal compressibilities (K-T,2(0)), excess partial molecular volumes (<(v)over bar (0,ex)(2)>) and partial molar heat capacity coefficients (partial derivative<(C)over bar (0)(p,2)>/partial derivative T)(p) of the various sugars have been calculated. The <(C)over bar (0)(p,2)> and <(V)over bar (0)(2)> values were found to be highly positive and increased with increase in temperature. High positive values of <(C)over bar (0)(p,2)> showed that the dissolution of the sugars was accompanied by the enhancement of the structural order in water. The results have been rationalized in terms of the specific hydration model.