The hydrated (with water) red form can be made by reacting cobalt(II) oxide or cobalt(II) hydroxide with hydrochloric acid.

The anhydrous (without water) blue form can be made by reacting cobalt with chlorine. If it is made, it just drops a Cl from CoCl 3, making CoCl 2 (cobalt(II) chloride) again. It can be oxidized to cobalt(III) compounds, although cobalt(III) chloride does not exist. Cobalt chloride can be used to test for chloride ions in this way. When it is heated, it turns more blue than when it is cooled.įor an example. Hydrochloric acid works the best, but sodium chloride can be used too. The green form is cobalt chloride reacted with a lot of hydrochloric acid.Ī different blue form is made when cobalt(II) chloride is reacted with a chemical compound that has chloride in it. The blue form is the color that it gives with some hydrochloric acid. The blue form will absorb water from the air and turn red again.Ĭobalt(II) chloride reacted with hydrochloric acid. It can be heated to turn it into the blue form, without water. It contains cobalt and chloride ions.Ĭobalt(II) chloride is normally found in the red (or pink) form. It contains cobalt in its +2 oxidation state. Except where otherwise noted, data are given for materials in their standard state (at 25 ☌, 100 kPa).Ĭobalt(II) chloride hexahydrate (with six water molecules attached) Cobalt(II) chloride anhydrous (with no water molecules attached)Ĭobalt(II) chloride, also known as cobaltous chloride and cobalt dichloride, is a chemical compound.

Cobalt chloride and water equation