ABSTRACT
Like the neighboring elements of the first transition series, nearly all the simple compounds of cobalt (Co) are of Co(II) oxidation state, since the Co(III) salts are practically confined to oxides, sulfides, sulfates, fluorides, and acetates; in fact, each of the latter three is considered to be a sort of complex. The addition of cyanide ions to a Co(II)(aq) solution results in the formation of the pentacyanocobaltate(II) ion which may be oxidized into aquopentacyano-eobaltate(III) ion. Compared with a number of studies on nickel and iron electrodes, very few studies have been made on cobalt. The anodic formation of particular cobalt oxides on the cobalt electrode has been reported by several investigators. Further, the charge used in the oxidation of cobalt was not completely recovered, the charge used in the oxidation of cobalt were not completely recovered, so that at the end of the experiment the electrode was always covered with brown film or blue film.
