Which solvent properties are important for effective recrystallization?

The correct choice emphasizes that for an effective recrystallization process, the solvent must have a key property: it should dissolve the compound of interest well at higher temperatures while being unable to dissolve it at lower temperatures. This selective solubility is crucial for the purification process.

During recrystallization, the compound is first dissolved in a hot solvent to form a saturated solution. As the solution cools, the solubility of the compound decreases, allowing it to crystallize out while impurities remain dissolved in the colder solute. This differential solubility is what facilitates the separation of the desired compound from impurities.

If a solvent did not possess this characteristic—meaning it could dissolve the compound at both high and low temperatures—the recrystallization process would be ineffective, as there would be no driving force for the compound to crystallize out of the solution as it cools. This highlights the importance of choosing a solvent that provides the right temperature-dependent solubility profile to achieve successful recrystallization.