Radiotracer Study of Synergistic Effects of Organophosphorus Compounds on the Extraction of Silver by N-(thio acetyl) benzamide into n-butanol

Abstract

The extraction behaviour of Ag(I) from an aqueous nitrate medium employing (N-thio acetyl) benzamide(HA) in n-butanol has been investigated in presence of several organophosphorus donors like, tri-butyl phosphine oxide, tri-phenyl phosphine oxide and tributyl phosphate at pH 4.0 adopting radio tracer technique. The synergism was found in presence of neutral donors due to the formation of the adduct [Ag (A) (H₂O) (B)] in n-butanol (B denotes neutral donor). The overall equilibrium constant for each of the three ternary complexes and also for binary system were calculated from extraction data. It was found that the extent of extraction of Ag (I) in organic phase both as the binary complex as well as ternary complex increased with increase in temperature. The temperature dependence of the equilibrium constants were investigated in order to evaluate the thermodynamic parameters like enthalpy (ΔH°), entropy (ΔS°) and free energy (ΔG°). Extraction mechanism was finally supported by I.R spectra of ternary adduct.