<unk> (II) chloride  is the chemical<unk> mpound with the formula<unk> Cl2, although the term is used also to refer to the hexahydrate, which is a different chemical<unk> mpound. <unk> Cl2 is blue, and<unk> Cl2·6H2O is deep magenta.  Because of this dramatic<unk> lor change and the ease of the hydration/dehydration reaction,<unk>  chloride" is used as an indicator for water. The magenta hexahydrate is probably the most familiar<unk> <unk> mpound in the laboratory.
Aqueous solutions of both<unk> Cl2 and the hydrate<unk> ntain the species trans-[CoCl2(H2O)4].  This is maintained in the solid state by the hexahydrate, the remaining two water molecules in its formula unit being water of crystallization. This species dissolves readily in water and alcohol. It has the interesting property that a<unk> ncentrated aqueous solution is red at room temperature, but becomes blue when heated.<unk> Cl2·6H2O is deliquescent and the anhydrous salt<unk> Cl2 is hygroscopic, readily<unk> nverting to the hydrate.
Cobalt
Chromate
Nickel
Lead
Opium
Organophosphorus
Bite
Ostium