Final answer:
A bad solvent for recrystallization may have high solubility for the compound at low temperatures, not distinguish well between solute and impurities, or have a melting point too close to the solute, which can lead to simultaneous crystallization of both.
Step-by-step explanation:
Properties of a Poor Solvent for Recrystallization
In the process of recrystallization, a solvent is chosen to dissolve a compound at high temperatures and allow it to recrystallize as the solution cools, leaving impurities in the solution. A bad solvent for this purpose often has properties that do not support this purification method. Some properties of such a poor solvent include high solubility of the compound at low temperatures, failing to differentiate between the solute and impurities, or a melting point that is too close to the solute, causing both to crystallize out simultaneously.
Ideal solvents for recrystallization should have opposite characteristics: they should dissolve a large amount of the solute at high temperatures and very little at low temperatures. Additionally, an ideal solvent should not react chemically with the solute, should have a lower boiling point than the solute to avoid decomposition, and should be volatile enough to be easily removed after the recrystallization process.