2. Influence of metal cation complexation or precipitation reagents

2.1 Reduction of a metal ion to the metal state

When metal ions in solution are complexed, we can assume that, if reactions are rapid (i.e. if equilibrium laws are respected), reduction takes place according to the following process: at the electrode surface, metal formation from M ^z+ cations left free (even in minute proportions) shifts complexation equilibria in the direction of complex dissociation (ML _i ) and, consequently, the release of the ligand (the complexing reagent) L.

This process is expressed by the following equations. At the electrode surface, electrochemical equilibrium continues to be expressed by the relationship :