Studies on the interactions behaviour of polyhydroxy solutes d(+)-glucose and d(−)-fructose in aqueous triammonium citrate solutions over temperature range T = (288.15-318.15) K

The interactions of polyhydroxy solutes d(+)-glucose and d(−)-fructose with aqueous solutions of triammonium citrate (TAC) as a function of temperature have been enquired upon by combination of volumetric and ultrasonic studies. Densities and speed of sound of d(+)-glucose and d(−)-fructose in (0.2, 0.4 and 0.6) mol·kg−1 aqueous solutions of triammonium citrate (TAC) are measured at T = (288.15, 298.15, 308.15 and 318.15) K and experimental pressure p = 0.1 MPa. The apparent molar volume, Vϕ, the partial molar volume Vϕo, and standard partial molar volumes of transfer, ΔVϕo for d(+)-glucose and d(−)-fructose from water to aqueous solutions of triammonium citrate (TAC) have been calculated from density data. Apparent molar isentropic compression, Kϕ,s, partial molar isentropic compression Kϕ,so and partial molar isentropic compression of transfer, ΔKϕ,so have been calculated from ultrasonic speed data. The expansibility parameter (∂Vϕ0/∂T)p and its derivative (∂2Vϕ0/∂2T)p along with pair (VAB, KAB) and triplet (VABB, KABB) interaction coefficients have also been calculated. The results have been interpreted in terms of solute-solute and solute-solvent interactions in these systems.