Investigation of the formation of zinc ethylenediaminetetraacetatozincate(II) by solubility measurements and electronic spectroscopy

The formation of zinc ethylenediaminetetraacetatozincate(II) according to the reaction ZnS + ZnEDTAS = Zn(ZnEDTA) in a solution of Na2(ZnEDTA) has been investigated spectrophotometrically and by solubility measurements. The solubility product SP = (7.3 +/- 0.65) x 10 U and the equilibrium constant K/sub D/ = (1.6 +/- 0.26) x 10, as well as the concentrations of the components ZnS , ZnEDTA, and Zn(ZnEDTA), have been determined. A conclusion regarding the structure of the compound studied has been drawn on the basis of a comparison of the absorption spectra of Zn(ZnEDTA) and zinc ethylenediaminetetraacetatozincate(II) hydrate, which was obtained from a saturated solution.