Separating Mixtures

• What are the four physical processes that can be used to separate mixtures?

  • Filtration
  • Crystallisation
  • Distillation
  • Fractional distillation
  • Chromatography
• What is filtration used to seperate?

  An undissolved solid from a solution
• What is crystallization used to seperate?

  A dissolved solid from a solution
• What is simple distillation used to sperate?

  Substances with boiling points far apart
• What is fractional distillation used to seperate?

  Substances with close boiling points
• How do you calculate the Rf values?

  Distance traveled by substance/ Distance traveled by solvent
• What is chromatography used to seperate?

  Substances in a mixture
• What is the stationary phase in chromatography?


  Chromatography paper
• What is the mobile phase in chromatography?

  Solvent
• How do you know if a substance is pure in chromatography?

  Produces one spot
• How do you know if a substance is impure in chromatography?

  Produces two or more spots
• How can you tell two substances are the same using a chromatogram?

  The spots travel the same distance, produce the same number of spots that match in colour