Investigations on the temperature dependent volumetric and ultrasonic properties of structural isomers D(+)-glucose and D(−)-fructose in aqueous dipotassium oxalate solutions

Abstract

The values of density, ρ and speed of sound, u for the saccharides that are structural isomers i.e. D(+)-glucose and D(−)-fructose in (0.2, 0.4, 0.6, and 0.8) mol·kg−1 aqueous solutions of dipotassium oxalate (K2C2O4) at T = (288.15, 298.15, 308.15 and 318.15)K have been measured in the present work. Various volumetric parameters such as apparent molar volume (Vϕ), partial molar volume at infinite dilution (Vϕo), transfer volume (ΔVϕo), have been derived from density records. Experimental values of the speed of sound were used to calculate ultrasonic parameters such as apparent molar isentropic compressibility (Kϕ,s), partial molar isentropic compressibility at infinite dilution (Kϕ,so), and partial molar isentropic compressibility of transfer (ΔKϕ,so). The pair (VAB, KAB) and triplet interaction (VABB, KABB) coefficients have been calculated from transfer parameters by using McMillan-Mayer theory. The structure-making/structure-breaking affinity of the saccharides along with a detailed insight into the physicochemical interactions e.g. ion-hydrophilic, hydrophilic–hydrophilic and hydrophilic-hydrophobic interactions in the saccharide-salt system, have been retrieved through the scrutiny of these calculated parameters.