A Mechanism for the Anodic Dissolution of Magnesium

Magnesium anodes were electrolyzed in 3% solution in a simple electrolysis cell. Mg in the anolyte, Mg in the corrosion product, total hydrogen evolved, and weight loss were determined. It was found that the quantities soluble Mg, insoluble Mg, Mg calculated from the current passed were in approximate one to one relationship with each other and all of these quantities are roughly half of the total weight loss. Hydrogen evolved was always slightly less than the soluble and insoluble Mg. These facts are explained and integrated into existing knowledge of the behavior of Mg anodes by postulating that Mg dissolves in the solution investigated mainly as a univalent ion followed by reaction of this univalent ion with water.