It is produced commercially mostly for laboratory work and is not as useful as the related compound iron(III) chloride.

In contrast, iron chlorides do not react with CO.

Gerhardt used iron chloride to detect acetone in diabetes (Gerhardt's reaction).

When chlorine comes into contact with heated iron, they react to form the black iron (III) chloride.

In the presence of iron(III) chloride as a catalyst, these compounds react exothermically:

Conservators then run mild currents through the recovered metallic parts, breaking up the corrosive iron chlorides.

Lewis acids such as boron trifluoride, zinc chloride, iron chloride, and aluminium chloride are also useful catalysts.

It can also be made by reacting iron(II) chloride with chlorine at a low temperature.

Other substances reputed to have been used by the English include Spanish fly, opium, watercress seed, iron sulphate, and iron chloride.

Add 9.94 g methyl ammonium chloride, 5.04 g anhydrous iron chloride into a 400 mL beaker.