Medium effects for single ions in acetonitrile and ethanol-water solvents based on reference-electrolyte assumption.

Medium effects, my, of several electrolytes in acetonitrile and ethanol-water solvents were calculated from new and literature data. In ethanol-water solvents, medium effects for single ions were estimated using the three assumptions that the values of log my of tetraphenylarsonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate, and triisoamyl-n-butylammonium tetraphenylborate, respectively, can be divided equally between their anions and cations. In acetonitrile, only the first two assumptions were applied. Excellent agreement was observed between the first two assumptions, while the third deviated from them by up to0.5 unit in log my. According to all three estimates of the medium effects for the proton, the basicity of ethanol-water mixtures is greater than that of the pure solvents and passes through a maximum. For ethanol-water solvents, the liquid-junction potentials at their interfaces with aqueous KCI and the potentials of the standard hydrogen electrodes referred to the aqueous SHE were calculated.

[1]  J. Coetzee,et al.  Solute-solvent interactions. VI. Specific interactions of tetraphenylarsonium, tetraphenylphosphonium, and tetraphenylborate ions with water and other solvents , 1971 .

[2]  R. Bates,et al.  Estimation of Medium Effects for Single Ions in Non-Aqueous Solvents , 1970 .

[3]  J. Coetzee,et al.  Polarography in sulfolane and reference of potentials in sulfolane and other nonaqueous solvents to the water scale , 1969 .

[4]  O. Popovych,et al.  Solubility products of potassium and triisoamyl-n-butylammonium picrates and tetraphenylborates in ethanol-water mixtures at 25.deg.C , 1969 .

[5]  O. Popovych,et al.  Electrolytic conductance and ionic association of several salts in ethanol-water mixtures , 1969 .

[6]  H. Friedman,et al.  The Gibbs free energy of transfer of the alkali perrhenates and perchlorates between pure water and pure nitromethane , 1968 .

[7]  R. Alexander,et al.  Solvation of ions. XIV. Protic-dipolar aprotic solvent effects on rates of bimolecular reactions. Solvent activity coefficients of reactants and transition states at 25°. , 1968 .

[8]  R. Alexander,et al.  Solvation of ions. XIII. Solvent activity coefficients of ions in protic and dipolar aprotic solvents. A comparison of extrathermodynamic assumptions , 1968 .

[9]  R. L. Kay,et al.  Conductance and association behavior of the alkali metal perchlorates and tetraphenylborides in anhydrous acetonitrile , 1967 .

[10]  R. Alexander,et al.  Solvation of ions. XII. Changes in the standard chemical potential of anions on transfer from protic to dipolar aprotic solvents , 1967 .

[11]  J. Coetzee,et al.  Solute-solvent interactions. I. Evaluations of relative activities of reference cations in acetonitrile and water , 1967 .

[12]  J. Coetzee,et al.  Solute-solvent interactions. II. Relative activities of anions in acetonitrile and water , 1967 .

[13]  R. Friedman,et al.  Solubilities of Potassium, Triisoamylbutylammonium, and Tetrabutylammonium Tetraphenylborides and Picrates in Water and Methanol and Their Medium Effects at 25° , 1966 .

[14]  O. Popovych.  Estimation of Medium Effects for Single Ions and Their Role in the Interpretation of Nonaqueous pH. , 1966 .

[15]  I. Kolthoff,et al.  Electrode Potentials in Acetonitrile. Estimation of the Liquid Junction Potential between Acetonitrile Solutions and the Aqueous Saturated Calomel Electrode1 , 1965 .

[16]  J. Coetzee,et al.  Evaluation of Single Ion Conductivities in Acetonitrile, Nitromethane, and Nitrobenzene Using Tetraisoamylammonium Tetraisoamylboride as Reference Electrolyte , 1965 .

[17]  R. Fuoss,et al.  Single Ion Conductances in Nonaqueous Solvents1,2 , 1964 .

[18]  M. Paabo,et al.  INTERPRETATION OF pH MEASUREMENTS IN ALCOHOL—WATER SOLVENTS1 , 1963 .

[19]  G. Baughman,et al.  The Solvation of Electrolytes in Dioxane-Water Mixtures, as Deduced from the Effect of Solvent Change on the Standard Partial Molar Free Energy1 , 1960 .

[20]  M. Born.  Volumen und Hydratationswärme der Ionen , 1920 .