Hey as Cobalt(II) chloride, also known as cobaltous chloride and cobalt dichloride, is a chemical compound.

Colour
Cobalt(II) chloride is normally found in the red (or pink) form. The red form has water in it. It can be heated to turn it into the blue form, without water. The blue form will absorb water from the air and turn red again.

Uses
It is used to place cobalt into other chemical compounds. It can be used to make other cobalt compounds. It is the most common cobalt compound in the lab.

Cobalt chloride
Cobalt(II) chloride is an inorganic compound of cobalt and chlorine, with the formula CoCl2.
It is usually supplied as the hexahydrate CoCl2•6H2O, which is one of the most commonly used cobalt compounds in the lab
The hexahydrate is deep purple in color, whereas the anhydrous form is sky blue. A blend would be mauve.
Because of the ease of the hydration/dehydration reaction, and the resulting color change, cobalt chloride is used as an indicator for water in desiccants.

Safety
In 2005–06, cobalt chloride was the eighth-most-prevalent allergen in patch tests (8.4%

Preparation
The anhydrous (without water) blue form can be made by reacting cobalt with chlorine.
The hydrated (with water) red form can be made by reacting cobalt(II) oxide or cobalt(II) hydroxide with hydrochloric acid.