Kinetics and Mechanism of Copper Dissolution in Aqueous Ammonia

The dissolution of copper in aqueous solutions of ammonia is a corrosion process in which the cathodic reaction is the reduction of oxygen at the surface of the metal according to: and the anodic reaction is the oxidation of copper according to: Superimposed with these reactions is the cuprous‐cupric equilibrium: A theoretical derivation of the velocity equation of the dissolution process has been obtained, which describes quantitatively the experimental facts. The equation is as follows: where k1, k2, k3 and f are constants, A is the surface area of the metal in contact with the aqueous phase and [O2], [NH3] and [Cu2+] are oxygen, ammonia and cupric ion concentrations respectively.