Zinc, if dissolved anodically in an aqueous 3 percent NaBrO3 solution apparently deviates from Faraday’s law in the sense that more Zn goes into solution than calculated. It can be proved that this disagreement is due to partial surface disintegration of the Zn anode while current is flowing. Very small particles of Zn are carried away from the anode when the surface oxide film detaches. The flakes are dark due to the presence of fine metallic particles. In moisture, the latter are oxidized quickly and turn white. The amount of disintegration (including the self-dissolution) is between 25 and 31 percent of the total Zn weight loss. Anodic disintegration decreases for Zn electrodes containing Au. The amount of disintegration is nearly Independent of the crystallographic plane of the single Zn crystal and agrees with that of a polycrystal. The reasons for and the mechanism of disintegration are discussed.

Subject
Films, Ions, Zinc anodes, Oxide films, Anode surfaces, Aqueous solutions, Metallic surfaces, Anodic dissolution, Electrochemical current, Oxide surfaces, Metals, Anodic current, Electrolytes
© 1966 National Association of Corrosion Engineers
1966
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