Ionic solubility equilibria calculations - a new approach

Abstract

In the classical approach, students have to verify assumptions using, amongst others, a "pure solution" or "the common-ion effect" concerning the situation they are studying to solve ionic solubility equilibria calculations. Furthermore, the simultaneous equilibria are shown in a non-trivial way. We propose a new way to understand these equilibria by implementing a method in which all conditions appear naturally in the mathematical equations. We present the Excess Parameter with solubility product equations to determine cation and anion's analytical and equilibrium concentrations. We consider the Bronsted ions acid-base behavior applying the equilibrium fractions (a). It is possible to use conditional Ksp (it involves Ksp and α) to ease calculations. Another option to solve calculations is to use the classical approximation or the iteration numerical calculations. This approach logically exposes concepts that we believe it is a good and promising method to teach and discuss Aqueous Solution Chemistry and Analytical Chemistry. [African Journal of Chemical Education—AJCE 13(3), July 2023]