Molar Solubility, Solvation and Conductivity Association Parameters of Sodium Fluoride in Mixed Aqueous-Ethanol Solvents at Different Temperatures

摘要

This paper reports the results on the molar solubility (MS), refractive index (RIN) and molar electrical conductance (EC) of the saturated NaF at different temperatures (293.15, 303.15 and 313.15 K) in mixed ethanol (ETOH) –water solvents. From the experimental part, the molar refraction (RM), limiting molar conductance (LEC), association constants (KASS), free energies of association (GASS) were determined for all solutions by using simple equation from the Shedlovslay model of conductivity.Results predicted the exothermic behaviour of the process in most of the cases. All the measured and calculated parameters for solvation (solubility parameters) and association (conductivity parameters) are increased by increasing the mole fraction of ethanol in the mixtures. This indicates more solute-solvent interaction by more adding ethanol in the mixed solvents.The solubility; conductivity and different thermodynamic data calculated here can easily used for the industial determination of sodium fluoride.