Final answer:
A beaker is not suited for recrystallization because its design does not allow for efficient heat transfer, leading to quick cooling and poor crystal formation, unlike narrow-necked flasks like Erlenmeyer flasks.
Step-by-step explanation:
A beaker is not a good vessel for recrystallization because it doesn't allow for efficient heat transfer. During recrystallization, a sample is dissolved in a hot solvent and then allowed to cool slowly. The slower the cooling process, the better the crystals can form. However, beakers have a wide open top, which can cause the solvent to cool too quickly, leading to poor crystal formation. Moreover, a beaker's shape is not conducive to minimizing solvent evaporation during the heating phase, which can also negatively affect the process. Instead, flasks, such as Erlenmeyer flasks or conical flasks, are preferred because their narrow neck minimizes solvent loss and ensures better temperature control.