Final answer:
Charcoal is added to a recrystallization solution to absorb impurities, enhancing the purity of the compound being recrystallized. Activated charcoal's ability to absorb a wide range of substances makes it an effective purifier in both drinking water and chemical preparations.
Step-by-step explanation:
Charcoal is often added to a recrystallization solution to remove impurities that may be present in a synthesized compound. The process of recrystallization involves dissolving the compound in a hot solvent to form a solution. As the solution cools, the compound becomes less soluble and starts to precipitate out, while the contaminating materials remain dissolved. Activated charcoal is used because it has the ability to absorb a wide range of substances, from colored organic particulates to inorganic metal ions, thus enhancing the purity of the recrystallized compound.
Specifically, charcoal is capable of removing the color of raw sugar and undesirable odor and taste in drinking water, suggesting its effectiveness in purifying chemicals as well. In the context of fractional crystallization, where the goal is to segregate a compound from its impurities, charcoal plays a critical role by absorbing impurities that might otherwise remain with the recrystallized product. When we mention seed crystal, it refers to a solid sample of the compound that is added to a supersaturated solution to facilitate the crystallization process, which is a separate technique from using charcoal.