
TY  - JOUR
A1  - Clare, BW 
A1  - Singh, P 
A1  - Mangano, P 
A1  - Parker, AJ 
A1  - Muir, DM 
T1  - Hydrometallurgical thermodynamics. I. Effect of sulfate ion-pairing and ion-solvation on the copper-iron redox equilibrium in aqueous acetonitrile
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1983
VL  - 36
IS  - 9
SP  - 1687
EP  - 1694
KW  - 
UR  - https://doi.org/10.1071/CH9831687 
N2  - The copper-iron redox equilibrium is shifted to the right CuII+FeII&#8596;CuI+FeIII by strong ion-pairing of sulfate ion with FeIII and by specific solvation of CuI with acetonitrile. The equilibrium constant has been measured by direct e.m.f. and spectroscopic methods between pH 0-2 and found to be about 107 higher for practical solutions of sulfates in acetonitrile/water than that calculated for perchlorates in pure water. Enthalpies and free energies of transfer of these ions from water to acetonitrile/water show that the shift in equilibrium to Cul+FeIII in acetonitrile/water solution is strongly favoured by enthalpy changes associated with copper(I)-acetonitrile ion-solvation. Ion-pairing of sulfate ion with iron(III) results in an increase in entropy and a small shift of the equilibrium to the right. 
ER  -

