The initial rate of dissolution of cadmium in various concentrations of carbon dioxide-free, air-saturated neutral salt solutions at 25 C was examined polarographically. The salts employed were potassium chloride, sodium chloride, barium chloride, potassium bromide, sodium bromide, potassium iodide, sodium iodide, sodium perchlorate, and barium perchlorate. The experiments were conducted in such a manner that the only variable was the concentration of salt in the solutions.
The order of reaction due to the salt was calculated at 25 C for the initial rate of dissolution of cadmium for each of the above salts. The nature of the anion was shown to have a much greater effect on the rate than does the nature of the cation. The perchlorate ion appears to act as an inhibitor and the iodide salts to have a maximum in the corrosion rate versus concentration curves. These results may be explained on the basis of anion polarization 4.3.6
