Potential-pH Diagram of Lead and its Applications to the Study of Lead Corrosion and to the Lead Storage Battery

The reactions and equilibrium equations of the system lead‐water are given in detail and are used in the construction of the potential‐pH diagram of lead. Some important features of the diagram are discussed, in particular the solubilities of oxides and hydroxides and some of the important oxidation reduction reactions. A modified form of the potential‐pH diagram of lead showing corrosion, passivity, and passivation domains is presented. The addition of passivation domains due to the presence of carbon dioxide and carbonates are determined. A modified potential‐pH diagram taking into account the presence of sulfate in solution is also presented. Important features of the behavior of lead storage batteries are studied on the basis of this modified diagram.