The Fundamental Equations of Electroplating

The fundamental equation for the overall reaction of metal deposition is 

Where M is any metal with a valency z. But this equation does not specify the phase in which each species is located and, more importantly, it does not take into account the role of the solvent. Both can be accounted for by rewriting this equation as 

in order to deposit a metal ion from solution it is necessary to remove all its solvation shell, which requires a lot of energy. This is not a thermodynamic barrier, since much of this energy is regained in the overall process. However, the high energy of hydration is expected to play a major role in the kinetics of the deposition process. 

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