Recrystallization Flow Chart Impure Crystalline Organic Compound X Hot Solution of Compound X And Impurities + Insolubles Hot Solution of Compound X And Impurities Less Insolubles Pure Precipitated Compound X Pure Dry Compound X Crystals Hot Solution of Compound X And Impurities 1) Test solubility of impure X in polar/non polar solvents at room/elevated temperatures. * For X, desire high solubility hot/low solubility cold. * For impurities, desire high solubility cold or high insolubility hot. 2) Heat to dissolve X in minimum amount of appropriate organic solvent. Filter hot thru filter paper or Celite pad to remove insolubles 1) Spontaneous crystallization may occur on cooling (use ice bath, if necessary); or 2) Induce crystallization, if necessary, by: * Partially concentrating the solution if too much solvent was used * Seeding or scratching 1) Filter to collect crystals 2) Wash crystals with small amount of cold solvent 3) Allow to dry Hot Solution of Compound X And Colored Impurities + Insolubles
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