Recrystallization

1. Recrystallization

2. Key Ideas
- In recrystallization, crude material is formed in
the minimum amount of hot solvent.
- The solution needs to cool slowly until one of
the compounds within the solution
recrystallizes while the other stays in liquid
phase.

3. There must be a difference in solubility to
separate the desired product from the
impurities.
• Typically organic compounds are more
soluble in hot solvent than cold.
• The compound being recrystallized should be
dissolved in hot solvent but be insoluble in
cold solvent.
Remember: “like dissolves like”
• Polar compounds dissolved in polar solvent, if
the polarities are too similar the compound
will dissolve but will not recrystallize.

4. Procedure for Recrystallization
Choose a solvent
Dissolve the solute in a minimum volume
Decolorize & Filter
All the system to cool slowly to crystallize
solute
Collect and wash crystals