A. Hubin et J. Vereecken, ELECTROCHEMICAL REDUCTION OF SILVER THIOSULFATE COMPLEXES .1. THERMODYNAMIC ASPECTS OF SOLUTION COMPOSITION, Journal of Applied Electrochemistry, 24(3), 1994, pp. 239-244
Deposition of silver from electrolyte solutions is of major importance
in the industrial applications of photographic development and electr
oplating. Prior to the kinetic study of the reduction of silver thiosu
lphate complexes, the concentrations, activities and activity coeffici
ents of all components formed in AgNO3-Na2S2O3-NaNO3 solutions are cal
culated, starting from the measurement of the equilibrium potential. I
n view of the high ionic strength of the solutions (greater than 0.1 m
ol kg-1), the ion interaction model is applied for the estimation of t
he activity coefficients, inevitably imposing the use of an iterative
calculation routine. The activity coefficients are shown to comply wit
h known thermodynamic laws, supporting the appropriateness of the mode
l, together with the approximations.