Under standard conditions, the voltage is commonly referred to as the standard emf or standard cell potential, E cell. A positive emf indicates a spontaneous process, while a negative emf indicates a nonspontaneous process. It is also clear that as the cell operates, reactant concentrations decrease as product concentrations increase, and so the cell potential decreases as the reaction proceeds. 85.6 Corrosion Corrosion is a redox reaction in which a metal is attacked by its environment to form an unwanted substance. All metals except gold and platinum, are thermodynamically capable of undergoing oxidation at room temperature.
Uninhibited corrosion can be very destructive.
Of commercial and governmental concern is the corrosion of iron. This process, commonly referred to as rusting, requires the presence of oxygen and water. The pH and the presence of salts and other metals more resistant to oxidation than iron can accelerate rusting. Corrosion Protection Plating metal with a thin layer of a less easily oxidized metal. Connecting to a sacrificial anode.