Final answer:
The choice of solvent in a recrystallization process is crucial as it minimizes impurity solubility at low temperatures, ensuring impurities remain in solution and the pure compound can crystallize out. Therefore, correct option is b.
Step-by-step explanation:
The most crucial aspect of a recrystallization procedure is the choice of solvent because it minimizes impurity solubility at low temperatures. When compounds are synthesized, they often have impurities mixed with them.
The recrystallization process aims to purify these compounds by dissolving the crystals in a hot solvent where the solubility is higher and then cooling the solution to precipitate the pure compound, leaving the impurities in the solution.
It is essential that the solvent selected can dissolve the compound at high temperatures but not at low temperatures, enhancing the selective crystallization of the pure compound upon cooling.
It's also important that the impurities are more soluble in the chosen solvent than the pure compound and, if possible, present in smaller amounts. This difference in solubility is what enables the separation during fractional crystallization.
Therefore, the correct choice of solvent significantly impacts the yield and purity of the recrystallized compound. This is because the correct solvent will ensure the impurities remain in the solution when it is cooled, allowing for the isolation of the purified compound through filtration.