Answer to Question #180711 in Organic Chemistry for Mohlolo

Question

Sometimes after obtaining a crude product we recrystallize it. What is meant by recrystallisazation and what is its purpose on the crude product?

Answer 1

Recrystallization is a procedure for purifying an impure compound in a solvent. The method of purification is based on the principle that the solubility of most solids increases with increased temperature. This means that as temperature increases, the amount of solute that can be dissolved in a solvent increases.When the temperature is high both solute and impurities are dissolved. Afterwards the temperature decreases (till room temperature, for example) and the solution becomes saturated in regard to solute but unsaturated in regard to impurities. This means that only solute will precipitate, impurities will be left in solvent.