Chemical Separation by Fractional Distillation and Crystallization
[caption id="attachment_24415" align="alignright" width="480"] Distillation apparatus[/caption] Solids may be subdivided into amorphous solids and crystalline solids. Amorphous solids possess limited order in the way molecules are bonded to each other. Crystalline solids, on the other hand, exhibit an exceptional degree of order. Logic should tell us a mixture of crystalline solids should be capable of chemical separation and purification through some reiterative crystallization process, based on relative solubilities. This proves to be true. The process is called fractional crystallization. Before discussing fractional crystallization, it might prove wise to discuss the simpler process of fractional distillation, the separating by distilling of a mixture of liquids possessing markedly different boiling points. Ordinary Distillation Consider an example of two liquids, Component A and Component B, that are miscible (they dissolve completely one within…