Spectrophotometric investigations of the reaction between gold(III) and potassium iodide

Abstract

The equilibria of the complex formation between AuCl4-n(OH)n- and I- was studied spectrophotometrically in aqueous solutions containing KI:Au(III)≤2 in the acidity range from 1 M HCl to pH 7 at 25 ºC. From the hydrogen ion and Cl- ion dependence of the absorption spectra, it was found that AuCl2I2- and Au(OH)2I2- complexes were formed. The equilibrium constants of complex formation were determined.

Ravnoteže obrazovanja kompleksa između AuCl4-n(OH)n i KI ispitivane su spektrofotometrijski u vodenim rastvorima pri odnosu koncentracija KI:Au(III) ≤ 2 u oblasti kiselosti od 1 M HCl do pH 7 na 25 ºC. Iz promene apsorpcionih spektara u zavisnosti od kiselosti sredine i koncentracije Cl- jona nađeno je da se obrazuju kompleksi AuCl2I2- i Au(OH)2I2-. Određene su konstante ravnoteže odgovarajućih reakcija. PR Projekat Ministarstva nauke Republike Srbije.