separating mixtures

• Mixtures


  Many mixtures contain useful substances. Examples include air, sea water, water in reservoirs and crude oil
• 5 Common Separation Methods

  • Magnetic attraction
  • Filtration
  • Evaporation
  • Distillation
  • Paper chromatography
• Magnetic attraction


  • Can be used to separate magnetic materials from those that are not attracted by magnets. Used in food processing and salvaging scrap iron and steel
• Filtration


  Separate an insoluble solid from a solid-liquid mixture
• Evaporation


  Separate a dissolved solid from a solid-liquid mixture
• Uses of Evaporation


  • To obtain salt from sea water
• Distillation


  Separate a pure liquid from a solid-liquid or liquid-liquid mixture
• Uses of Distillation


  • To make perfumes
  • Desalination plant
  • To make distilled water (pure H2O)
• Fractional Distillation


  Used to separate more than two liquids in a mixture of miscible liquids. Oil refineries use it to separate crude oil into useful products
• Paper Chromatography


  Used to separate small amounts of mixtures. Makes use of the fact that different substances dissolve to different extent in a mixture
• Uses of Paper Chromatography

  • To find the dyes used in ink
  • To find the dyes used in food
• Other Separation Methods


  • Manual Separation
  • Sifting
• Manual Separation


  Physically separate parts of a mixture using your fingers
• Sifting


  Use a sieve or sifter to separate larger solids from smaller ones