Journal of Applied Electrochemistry

, Volume 24, Issue 3, pp 239–244 | Cite as

Electrochemical reduction of silver thiosulphate complexes Part I: Thermodynamic aspects of solution composition

  • A. Hubin
  • J. Vereecken
Papers
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Revised:

Abstract

Deposition of silver from electrolyte solutions is of major importance in the industrial applications of photographic development and electroplating. Prior to the kinetic study of the reduction of silver thiosulphate complexes, the concentrations, activities and activity coefficients of all components formed in AgNO3-Na2S2O3-NaNO3 solutions are calculated, starting from the measurement of the equilibrium potential. In view of the high ionic strength of the solutions (greater than 0.1 mol kg−1), the ion interaction model is applied for the estimation of the activity coefficients, inevitably imposing the use of an iterative calculation routine. The activity coefficients are shown to comply with known thermodynamic laws, supporting the appropriateness of the model, together with the approximations.

Keywords

Ionic Strength Industrial Application Kinetic Study Activity Coefficient Electrolyte Solution 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

List of symbols

a

activity (m)

c

concentration (m)

d

density (kg dm−3)

h

hydration number

m

molality (mol kg−1)

x

molfraction

y

activity coefficient (molarity scale)

z

charge of an ion

E0

equilibrium potential vs NHE (V)

I

ionic strength (m or mol kg−1)

M

molecular weight (kg dm−3)

T

temperature (K)

Greek symbols

β

stability constant

γ

activity coefficient (molality scale)

ν

stoichiometric coefficient

ϕ

osmotic coefficient Indices

Indices

f

free (uncomplexed)

s

solvent

t

total

− (or a)

anion

+ (or c)

cation

±

mean quantity

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References

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Copyright information

© Chapman & Hall 1994

Authors and Affiliations

  • A. Hubin
    • 1
  • J. Vereecken
    • 1
  1. 1.Department of Metallurgy, Electrochemistry and Materials ScienceVrije Universiteit BrusselBrusselsBelgium

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