Question

If charcoal and sugar were the the main impurities present in crude acetanilide would recrystallisation from water be a good method of purification explain why?

Answer 1

Yes, recrystallization from water would be a viable technique of purification if crude acetanilide contained sugar and charcoal. Due to their physical insolubility, charcoal found in crude acetanilide and water will form a heterogeneous combination. Charcoal will separate during crystallization because it is insoluble in water. Sugar and the unreconstituted crude acetanilide make up the remaining portion of the combination. Crude acetanilide will crystallize in this combination and separate from the sugar and water solution. Filtration will be used to capture the crude acetanilide that has solidified. Sugar and water make a soluble solution, thus they are kept separate. This is how the charcoal and sugar combination is purified and its constituent parts are separated from crude acetanilide using the recrystallization process from water.