C1.1.2 - Mixtures

• Are the properties of substances in Mixtures changed?

  No.
• What are the 5 processes that can be used to separate mixtures?

  Non chemical ways

  • Filtration. (Insoluble solids from liquids)
  • Crystallisation.(soluble solids from liquids)
  • Paper Chromatography. (Different dyes)
  • Simple Distillation. (Liquid from solution)
  • Fractional Distillation. (Liquids with diff boiling points)
• Filtration

  1. One beaker contains a mixture of solid and liquid. The other contains a funnel with filter paper.
  2. The solid and liquid mixture is poured into the filter funnel.
  3. The filter paper holds back the solid particles while allowing the liquid to drip through.

  
• Crystallisation

  1. A solution is placed in an evaporating basin and heated with a Bunsen burner.
  2. The water evaporates, reducing the solution’s volume. Solid particles begin to form in the basin.

  
• Distillation

  1. Salty water is heated.
  2. The water vapour cools in the condenser and drips into a beaker.
  3. The water has condensed as a distillate in the beaker. The salt stays behind.

  
• Fractional Distillation

  1. Heat the water and ethanol solution.
  2. The ethanol evaporates first, cools, then condenses.
  3. The remaining water evaporates, cools and condenses.

  
• Paper Chromatography

  1. Spots of ink or plant dye are placed on a pencil line.
  2. Some of the dye spreads up the paper as it is lowered into the solvent.

  3. The dye spreads up the paper as it absorbs the solvent.

  
• Choosing a method of separation

  Insoluble solid and liquid -> Filtration e.g. Sand and water

  Soluble solid and liquid (solution) -> Crystallisation (by evaporation) e.g. Salt water (sodium chloride solution)

  Two miscible liquids -> Distillation e.g. Ethanol and water

  Soluble solids dissolved in a solvent -> Paper chromatography e.g. Food colourings, dyes and inks