Stabilité des complexes hydroxo et produits de solubilité des hydroxydes de métaux. I. Argent et zinc

Abstract

Recu le 25 aoClt 1966On a procCdC A une dCtermination des complexes hydroxo d'argent et de zinc A partir des courbes de solubilitC des hydroxydes en fonction du pH, A 25 "C et force ionique unitaire (NaC104). On a calcul6 les produits de solubilit6 des hydroxydes et les constantes de formation des espkces AgOH, Ag(0H)z-, ZnOH+, Zn(OH)z, Zn(0H)r-et Zn(OH)42-.The hydroxo-complexes of silver and zinc are determined from a plot of their hydroxide solubility curves vs. pH, a t 25 OC and unit ionic strength (NaC104). The hydroxide solubility products and the formation constants of AgOH, Ag(0H)z-, ZnOHf, Zn(OH)z, Zn(OH)a-, and Zn(OH)42-are calculated.

Zinc Electrode Cycle-Life Performance in Alkaline Electrolytes Having Reduced Zinc Species Solubility

“…The aqueous hydroxyl group forms complexes wi th Zn for which the coefficients of complex formation have been reported (Reichle et aI, 1975;Gubeli and Ste-Marie, 1967). Solubility products for zinc hydroxide have also been reported (Reichle et aI, 1975;Pourbaix, 1974).…”

“…At high hydroxyl-ion concentrations the hydroxyl group is believed (Reichle et aI, 1975;Gubeli and Ste-Marie, 1967;Dirkse, 1981) to -5-2+ tetrahedrally complex the Zft ion, and the ove~all complex-formation reaction has the following equilibrium expression:…”

The purification of fructose 1,6-diphosphatase from ox liver and its activation by ethylenediaminetetra-acetate

“…of Zn(OH)2 is about 16 (Gubeli & Sainte-Marie, 1967), so that lpM-Zn2+ would be expected to precipitate as Zn(OH)2 between pH9 and 10, whereas the pKa values of fructose diphosphate seem to be below pH7 (McGilvery, 1965). It therefore seems likely that the 'titration curve' observed in Fig.…”

The complexing characteristics of insoluble selenides. 1. Silver selenide

“…I t is, nevertheless, clear that the increase in the solubility of the selenide precipitate is not due to any hydroxy complex formation as found in an independent investigation on the solubility characteristics of silver oxide (17). If it were so, the solubility in alkaline medium would have decreased as a function of increasing selenide concentration, even though a positive slope of unity as a function of pH might still remain the principal solubility feature.…”