The complexing characteristics of insoluble selenides. 1. Silver selenide

Abstract

The aqueous solubility of the system silver selenide has been investigated in an inert atmosphere of nitrogen at a unit molar ionic strength and constant temperature of 25° C. The experimental evidence indicates the formation of two aqueous species [Ag2(HSe)(OH)], and [Ag(Se)2(OH)]4− in contact with the precipitated selenide in different regions of acidity. The former exists in acidic medium and has a pβ value of 48.49 ± 0.10 while the latter is stable only in alkaline conditions and has a pβ value of 24.07 ± 0.19. A mathematical treatment has been elaborated to identify and calculate the stability constants of such selenide complexes formed through a heterogeneous equilibrium.