The physico-chemical properties namely viscosity (Î·), surface tension (Î³), conductance (Îš), molar conductance (Î¼), and thermodynamic parameters like enthalpy change of activation (Î”H*), entropy change of activation (Î”S*), free energy change of activation (Î”G*), molar heat capacity change at constant volume (Î”Cv) and molar heat capacity change at constant pressure (Î”Cp) of potassium iodide solutions in varying compositions (1%v/v to 5%v/v) of sunflower oil-DMF and maize oil-DMF solvent were measured at temperatures of 303 to 323K with a difference of 5K. The range of potassium iodide concentration was from 1.0 Ã— 10-2 to 9.0 Ã— 10-2 mol.dm-3. The physico-chemical properties were used to evaluate the fundamental changes in properties of potassium iodide solutions with changes in concentration of different components and experimental temperature whereas the thermodynamic parameters were used for evaluation of the magnitude and nature of different energy changes involved in the formation of various compositions of potassium iodide solutions. The viscosity data indicated the increase in ion-solvent interactions with temperature characteristic of structure-breaking electrolytes. The thermodynamic data and molar heat capacities indicated that the process of formation of potassium iodide solution in edible oil-DMF solvent is endothermic in nature. The results are explained in terms of structural interactions and energetics of the processes involved.
Key words: Viscosity, edible oil, thermodynamic parameters, molar heat capacity, ion-solvent interactions.
Keywords: Viscosity, edible oil, thermodynamic parameters, molar heat capacity, ion-solvent interactions.