Why is methanol a good solvent to recrystallize biphenyl?
Methanol is a good solvent for recrystallizing biphenyl due to several reasons. First, methanol has a high polarity and can dissolve a wide range of organic compounds, including biphenyl. This property makes methanol an excellent choice as a solvent to dissolve the impure biphenyl.
To begin the recrystallization process, you would typically dissolve the impure biphenyl in hot methanol. The high solubility of biphenyl in methanol at elevated temperatures would ensure that most of the biphenyl dissolves, leaving behind the impurities.
Next, as the methanol cools, the solubility of biphenyl decreases, causing the biphenyl molecules to come out of solution and form crystals. During this phase, the impurities are excluded from the growing crystals, resulting in a purer final product.
Moreover, methanol has a relatively low boiling point, making it easy to remove any remaining solvent after the recrystallization process through evaporation. This ensures that the recovered biphenyl is free from any solvent traces.
Overall, the high polarity, wide solubility range, and low boiling point of methanol make it an ideal solvent for the recrystallization of biphenyl, leading to a purified final product.