Cobaltic hydroxide, Co(OH) 31 is formed when a cobalt salt is precipitated by an alkaline hypochlorite, or on passing chlorine through water containing suspended cobaltous hydroxide or carbonate.
This hydroxide is soluble in well cooled acids, forming solutions which contain cobaltic salts, one of the most stable of which is the acetate.
Electrolysis of a solution in hydrofluoric acid gives cobaltic fluoride, CoF3.
The cobaltic salts corresponding to the oxide Co 2 0 3 are generally unstable compounds which exist only in solution.
59, p. 760) has prepared cobaltic sulphate C02(S04)3.18H20, in the form of small needles, by the electrolysis of cobalt sulphate.
The double salts containing the metal in the cobaltic form are more stable than the corresponding single salts, and of these potassium cobaltinitrite, C02(N02) 6 '6KN02.3H20, is best known.