The formation of a film by the bromide salt of the cation radical of heptyl viologen, HV.1, on a polycrystalline silver electrode under potentiostatic conditions can be interpreted in the light of an adsorption-nucleation mechanism and a diffusion-controlled growth mechanism. On the other hand, the dissolution of such a film can be interpreted with the aid of a mathematical model based on a progressive hole-nucleation and layer-by-layer growth of vacancies that considers dissolution of incomplete monolayers.