
TY  - JOUR
A1  - Muir, DM 
A1  - Singh, P 
A1  - Kenna, CC 
A1  - Tsuchida, N 
A1  - Benari, MD 
T1  - Hydrometallurgical Thermodynamics. II. Solvent Effects on the Activity and Free Energies of Transfer of CN-, Ag(CN)<sub>2</sub>- and Au(CN)<sub>2</sub>- in Ethanol-Water and Acetonitrile-Water Mixtures
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1985
VL  - 38
IS  - 7
SP  - 1079
EP  - 1090
KW  - 
UR  - https://doi.org/10.1071/CH9851079 
N2  - The free energies of transfer of CN-, Ag(CN)2- and Au(CN)2- ions from water to a range of acetonitrile -water and ethanol-water mixtures are reported. The values are based upon measurements of solubility products and formation constants of AgCN and Ag(CN)2-, and upon measurements of the Au(CN)2-/Au couple, by using known values of &#916;Gtr(Ag+) based on the tetraphenylarsonium  tetraphenylborate ( tatb ) assumption. Addition of acetonitrile to water increases the activity of these ions in the order CN- > Ag(CN)2- &#8805; Au(CN)2- much more than the addition of ethanol. Solvent effects on CN- and Ag(CN)2- are similar but slightly less than those on Cl - and AgCl2-, and show no special ion-solvent interactions between MeCN and CN-. The relative activity of CN- and Au(CN)2- in aqueous-organic mixtures rationalizes the ability of such mixtures to desorb gold from the activated carbon used in gold processing through an ion-exchange mechanism. 
ER  -

