Metal in seawater is one such example with the iron metal coming into contact with electrolytes. Under normal circumstances, the iron metal would react with the electrolytes and begin to corrode, growing weaker in structure and disintegrating. The addition of zinc, a sacrificial anode, would prevent the iron metal from “corroding”. According to the table of Standard Reduction Potentials, the standard reduction potential of zinc is about -0.76 volts. The standard reduction potential of iron is about -0.44 volts. This difference in reduction potential means that Zinc would oxidize much faster than iron would. In fact, zinc would oxidize completely before iron would begin to react.
The materials used for sacrificial anodes are either relatively pure active metals, such as zinc or magnesium, or are magnesium or aluminium alloys that have been specifically developed for use as sacrificial anodes.
The materials used for sacrificial anodes are either relatively pure active metals, such as zinc or magnesium, or are magnesium or aluminium alloys that have been specifically developed for use as sacrificial anodes.