Cobalt iodate, decomposition

Anhydrous cobalt iodate yields microscopic needles, blue-violet in colour, and which on heating become dark blue in colour, but regain their original hue on cooling. Below 200° C. decomposition sets in, iodine and oxygen being evolved. 

The decompositions of cobalt and nickel iodates [37] at 688 K and above 763 K, respectively, yield the metal oxide and iodine. In hydrogen, Nilj is reduced to metal and HI at about 770 K, but the reaction of C0I2 is slower. Ni(I03)2.2H20 and Zn(I03)2.2H20 dehydrate in a single stage, followed by decomposition to the oxides [42]. The deuterates were more stable because of structural changes. 

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