Conductivity in NiSO4–d-glucose–water solutions at 278.15–308.15 K

Viscosities and densities of d-glucose–water mixtures were measured, and conductivities in the NiSO4–d-glucose–water system were also measured at 278.15–308.15 K in 5 K intervals. Based on the Lee–Wheaton conductivity equation, values of limiting molar conductivities Λ0 and association constants KA were obtained. Changes in the standard thermodynamic functions, Gibbs energy ΔGA°(T), enthalpy ΔHA°(T), and entropy ΔSA°(T), for a process of ion-pair formation were calculated at different temperatures. The results show that (1) at given temperatures, the Λ0 values for 1/2NiSO4 decrease with increasing concentrations of d-glucose; (2) at fixed concentrations of d-glucose, the Λ0 values for 1/2NiSO4 increase with increasing temperature; and (3) the process of association of NiSO4 is controlled by the change in entropy ΔSA°.