Ion-Solvation and Ion-Association Behavior of Tetraphenylphosphonium Chloride, Sodium Tetraphenylborate and Sodium Chloride in Polyethylene Glycol plus Water Mixtures at 298.15K

Electrical conductances of solutions of tetraphenylphosphonium chloride, sodium tetraphenylborate, and sodium chloride in polyethylene glycol (PEG)+water mixed solvent systems having 0.200, 0.400, and 0.600 mass fractions of PEG are reported at 298.15K. In this study three different average molar masses of PEG, e.g., 300 (designated as PEG 300), 400 (designated as PEG 400), and 600 (designated as PEG 600) gmol(-1) were employed. The conductance data have been analyzed using the 1978 Fuoss conductance-concentration equation in terms of the limiting molar conductance, the association constant and the association diameter of the electrolytes. The ionic contributions to the limiting molar conductances have been estimated using tetraphenylphosphonium tetraphenylborate as the reference electrolyte, considering the similarity of the sizes and chemical characters of the tetraphenylphosphonium and tetraphenylborate ions possessing a quasi-spherical surface of the phenyl rings. Analyses of the results provided important information as to the ion-association and solvation behavior of the electrolytes/ions investigated in PEG+water mixed solvent media.