Hydrated calcium chloride when fused loses water of crystallization to form anhydrous calcium chloride but anhydrous magnesium chloride cannot be prepared by heating magnesium chloride hexahydrate . Why so ?

Hydrated calcium chloride when fused loses water of crystallization to

1.	Hydrated calcium chloride when fused loses water of crystallization to form anhydrous calcium chloride but anhydrous magnesium chloride cannot be prepared by heating magnesium chloride hexahydrate . Why so ?
Answer» Solution :ANHYDROUS `MgCl_(2)` cannot be prepared by simply heating `MgCl_(2) . 6 H_(2)O` because it gets hydrolysed by its own water of crystallization . `MgCl_(2) + 6H_(2)O to Mg O + 2 HCL + 5 H_(2)O` However , if hydrated magnesium chloride is heated in an atmosphere of HCl GAS at 650 K, it checks the above hydrolysis reaction and the hydrated magnesium chloride now loses water of crystallization to form anhydrous magnesium chloride now loses water of crystallization to form anhydrous magnesium chloride `MgCl_(2) . 6 H_(2)O overset(HCl "gas")underset(650K)(to) MgCl_(2) + 6 H_(2)O`.