Re-evaluation of the Thermodynamic Activity Quantities in Aqueous Solutions of Silver Nitrate, Alkali Metal Fluorides and Nitrites, and Dihydrogen Phosphate, Dihydrogen Arsenate, and Thiocyanate Salts with Sodium and Potassium Ions at 25 °C

Abstract

The Huckel equation used in this study to correlate the experimental activities of dilute solutions of silver nitrate, alkali metal fluorides, and sodium and potassium salts with dihydrogen phosphate, dihydrogen arsenate, and thiocyanate ions up to a molality of about 1.5 mol·kg−1 contains two parameters being dependent on the electrolyte: B [that is related closely to the ion-size parameter (a*) in the Debye−Huckel equation] and b1 (this parameter is the coefficient of the linear term with respect to the molality, and this coefficient is related to hydration numbers of the ions of the electrolyte). In more concentrated solutions of these electrolytes and of alkali metal nitrites in the best case up to a molality of 10 mol·kg−1, an extended Huckel equation was used; it contains additionally a quadratic term with respect to the molality, and the coefficient of this term is the parameter b2. All parameter values for the Huckel equations of AgNO3 solutions were determined from the isopiestic data measured by...