Extraction of AuCl4- from HCl solutions by the chloride salt of the secondary amine Amberlite LA2 and estimation of the interaction coefficient between AuCl4- and H+

Abstract
The equilibrium distribution of AuCl4- between hydrochloric acid and the chloride salt of the secondary amine Amberlite LA2 in xylene was investigated. The extraction reaction is exothermic (ΔH° = −20.8 kJ/mol). The stoi-chiometry of the complex formed in the organic phase can be represented by R'R″NHH+AuCl4- and the extraction equilibrium constant depends on the ionic strength. From this dependency it was found that log K° = 3.9 and the interaction coefficient between AuCl4- and H+ is 0.24.