Buffering properties of heterogeneous water-salt systems in relation to the components of a low-solubility precipitate

Quantitative aspects of the buffer action of heterogeneous systems that contain a low-solubility salt (solid phase) and a saturated multicomponent solution (liquid phase) are presented. The buffering properties relative to the ions of the precipitate are enhanced by side protolytic reactions or complexing reactions occurring in solution. A simple method is advanced to evaluate the buffer action based on the tabulated solubilities or solubility products of a low-solubility compound. The buffer action of a heterogeneous system is a function of precipitate stoichiometry. The applicability limits of the relationships are specified, and sample calculations of the functions for particular systems are given.