Cobalt chloride

[structure or molecular formula]

CoCl ₂ ·6H ₂ O

[density] relative density (25 ° C): 1.925 (six water), 3.356 (anhydrous)

[melting point (°C)] 86 (six water)

【Properties】

Hexahydrate: red crystal, anhydrate: light blue powder.

【Solubility】

Liushui: soluble in water, soluble in ethanol, ether and acetone; anhydrous: soluble in ethanol, acetone, nitrobenzene.

【use】

Used in the manufacture of barometers, hydrometers, hidden inks, etc. The cobalt chloride test paper is blue when dry and turns pink when wet. A certain amount of cobalt chloride is added to the silica gel to indicate the degree of moisture absorption of the silica gel.

[preparation or source]

It is prepared by the action of cobalt oxide and hydrochloric acid.

【other】

The hexahydrate is deliquescent in the air, and when it is heated to 120-140 ° C, it loses crystal water and becomes an anhydrate.