Rutgers Organic Chemistry Laboratory Practice Exam

The common solvent used for recrystallization of organic compounds is based on the principle that the solvent must be able to dissolve the compound at high temperatures, while allowing the compound to crystallize at lower temperatures. Ethanol, water, and acetone are versatile solvents often utilized in recrystallization processes because their boiling points and solubility properties can be selected based on the specific compound being purified.

Ethanol is frequently used for a variety of organic compounds; water is an excellent choice for polar compounds; and acetone works well for compounds that are moderately polar. The ability to choose from these different solvents allows for a more tailored and effective recrystallization process.

In contrast, other solvents listed may not offer the necessary solubility characteristics for recrystallization. For instance, hexane is generally more suitable for non-polar compounds and may not effectively dissolve many organic compounds that require purification. Aqueous hydrochloric acid is unlikely to be used as a recrystallization solvent since it is a strong acid that might lead to decomposition or undesirable reactions with organic compounds. Benzene and toluene are less commonly used due to their environmental and health concerns, and they may not provide the optimal solubility behavior for recrystallization like ethanol,