Cobalt chloride can be used for the synthesis of many complexes, such as Hexamminecobalt (III) chloride and Potassium cobaltinitrite.It can also be found in some types of colored silica gel, though the amount is small.Ĭobalt(II) chloride, along with other cobalt(II) compounds is classified as 'Substance of very high concern' in the EU and its sale is regulated. If heptahydrate crystals are desired the solution may be dried in a desiccator.Ĭobalt(II) chloride can be purchased from chemical suppliers, both as a solid and as a solution. Usually, there will be a layer of unreacted cobalt carbonate/other contaminants that must be filtered out using either vacuum or gravity filtration in order to receive a pure product.īy heating this solution to dryness a light blue powder will be formed which is anhydrous cobalt chloride. Add a small amount of acid and then stir the mixture before adding another small portion, as the CO2 created can cause the mixture to overflow. The density for the three forms is 3.356 g/cm 3 (anhydrous), 2.477 g/cm 3 (dihydrate), 1.924 g/cm 3 (heptahydrate).Ĭobalt chloride heptahydrate can be synthesized by reacting two moles of hydrochloric acid with one mole of cobalt carbonate.

CoCl 2 is soluble in water (52.9 g/100 mL at 20 ☌) methanol (38.5 g/100 mL), and slightly soluble in acetone, diethyl ether. The compound melts at 735 ☌ (anhydrous), 100 ☌ (dihydrate), 86 ☌ (hexahydrate). Cobalt(II) chloride is a salt that is blue when anhydrous and pink-purple when hydrated.

Cobalt chloride and water equation