Die Löslichkeit von Metallsulfiden I. Schwarzes Quecksilbersulfid

Abstract

Abstract The total concentration of dissolved mercury in equilibrium with solid HgS and in the presence of excess sulfide (present in the form of H 2 S, HS‐ and S 2− has been determined radiochemically and gravimetrically. The difficult problem of the clean separation of the precipitated HgS from the solution could be solved by very slow filtration of large quantities of the suspension through a small porous plate under constant pressure. The solubility at a constant concentration of excess sulfide (=0,019 molar) as a function of pH is demonstrated in figure 1. The solubility is due to the complex Hg(SH) 2 below pH 5, the complex HS‐Hg‐S‐ between pH 6 and 8, and the complex HgS above pH 9. The solubility produce of black HgS, the stability constants of the complexes, and the two acidity constants of Hg(SH) 2 are given in the last section of the paper.