Recrystallization is a laboratory technique used to purify solids based on their different solubilities. A small amount of solvent
is added to a flask
containing an impure solid. The contents of the flask are heated until the solid dissolves. Next, the solution
is cooled. A more pure solid precipitates, leaving impurities dissolved in the solvent. Vacuum filtration is used to isolate the crystals. The waste solution is discarded.
Summary of Recrystallization Steps
- Add a small quantity of appropriate solvent to an impure solid.
- Apply heat to dissolve the solid.
- Cool the solution to crystallize the product.
- Use vacuum fitration to isolate and dry the purified solid.
Let's take a look at the details of the recrystallization process.