Question

Explain why:
Fused calcium chloride is used in the preparation of $FeC{l_3}$

Answer 1

Fused calcium chloride is an anhydrous salt. It is formed by electrolysis and fusion. It is highly absorbing in nature. $FeC{l_3}$ is very deliquescent when it is present in an anhydrous form. It is used in organic synthesis as a catalyst.

Complete answer:
$FeC{l_3}$ is ferric chloride. It is a dark color crystal. It is also known as Iron (III) chloride or Molysite. Its smell is faintly like that of hydrochloric acid (HCl). It is a strong Lewis acid. Ferric chloride is highly corrosive to metals. It is also an astringent; it can constrict or shrink body tissues.
In the fused form and the anhydrous form of calcium chloride, there is no difference when it comes to the theory part. But when it comes to practicing the fused form of calcium chloride is solid having higher moisture content and when this fused calcium carbonate is heated to expel out the water content it becomes anhydrous calcium carbonate.
The anhydrous form of ferric chloride is very much deliquescent; this means that it absorbs the moisture from the atmosphere until it dissolves in the absorbed water and forms a solution. This solution is called hygroscopic liquid. So in order to keep the ferric chloride dry, fused calcium chloride is used for its preparation.

Note:
Just like ferric chloride, fused calcium chloride is hygroscopic and they both absorb the moisture from the atmosphere when exposed to air but in the case of fused calcium chloride, it does not change its state where ferric chloride changes and becomes liquid from solid. Fused calcium chloride because of its hygroscopic nature is also used as a drying agent in desiccators.