One of the most important contributions to corrosion literature in recent years has been the work of Pourbaix and associates in the development of thermodynamic equilibrium diagrams (Potential vs pH) for the behavior of metals in aqueous solutions.1 A vast amount of data can be organized economically and fruitfully in Pourbaix diagrams.
Construction of these diagrams from thermodynamic data actually is relatively simple. Unfortunately, the procedure suggested in the literature1 for calculating equations used in constructing them is unnecessarily abstract and confusing. Hence, those encountering the subject for the first time are likely either to waste considerable time trying to attach physical significance to the mathematical manipulations suggested, or to abandon the idea altogether. To avoid both of these eventualities, the author presents herein a procedure, based on the direct use Of the Nernst equation, which has been successful in presenting the subject to students. Final results are...
