Magnesium, because of its position in the electrochemical series, has long been thought of as an ideal source of current for cathodic installations. Adding credence to this belief is its high electrochemical equivalent of 1,000 ampere-hours per pound and solution potential to a CuSO4 electrode of from 1.8 to 1.7 volts depending upon whether commercially pure or alloyed material is used. By comparison, zinc has an electrochemical equivalent of 372 ampere-hours per pound and a solution potential of approximately 1.1 volts.
From the ratio of electrochemical equivalents, it is evident that magnesium at a current efficiency of only would be equivalent to zinc at a current efficiency of 90%. However, much higher efficiencies than this have been obtained on magnesium in field installations. It is to be noted that the difference in solution potentials of the metals is an additional factor to be considered. Assuming...
