Concept:Recrystallization is a purification method that separates a solid solute from impurities using differences in solubility at different temperatures.
Explanation:Dissolve the impure solid in a minimum amount of hot solvent.
As the solution cools, the pure solute crystallizes out because the solution becomes saturated.
Impurities remain dissolved in the mother liquor and are removed by filtration.
This method yields crystals of very high purity, often up to
99.9%.
Distillation mainly separates liquid mixtures by boiling point, not solid solutes.
Sieving separates by particle size, and precipitation often traps impurities.
Thus, recrystallization is the best choice when purity of the solute is most important.
Answer:C. Recrystallization