Studies of Cobalt II Compounds

The cobalt salts available are those of Co(ll) which are pink in colour. On the other hand, Co(II) complexes are fewer and generally less stable than those of Co(IIl). In fact, in presence of numerous ligands, Co(II) is readily oxidised to the inert Co(IlI) complexes. Cobalt(II) has a tendency to form intensely coloured tetrahedral complexes, generally with anionic ligands. 

There are fewer analytical methods for Co(II) compared to other 3d metals. 

This is the simplest method when high concentrations of other elements are absent. 

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