Separation techniques

• What is dissolving?


  When a substance splits up and mixes with a liquid

  to form a solution
• Soluble is When a substance can dissolve in a liquid.
• insoluble is When a substance does not dissolve in a liquid.
• The substance dissolved in a solution is a solute
• solvent is A liquid used to dissolve things.
• A solution is when a solid is dissolved in a liquid.
• chromatography is used to separate mixture of coloured compounds
• How does Chromatography work

  • Most inks are soluble in water
  • Different colour pigments are more soluble than others
  • Each colour will move a different distance up the paper
• Filtration is used to separate insoluble solids and liquids
• Filtration works by the

  • solution ( water ) will pass through the filter paper and insoluble substances ( sand ) will not
• Magnetism is used to separate magnetic substances from non-magnetic substances.
• Magnetism works by

  • applying a magnet to the mixture
  • magnetic substances will attract, non-magnetic will not
• A separating funnel is used to separate mixtures of immiscible liquids
• How does a separating funnel work

  • It allows immiscible liquids to form layers
  • open tap to let the bottom layer out
• Crystallisation is used to separate dissolved salts and their solvent
• How does crystallisation work

  • Heat mixture until solution starts to evaporate
  • This leaves the salt crystals behind
• What is fractional distillation used to separate?

  Mixture of liquids with many different boiling points
• What is the technique, simple distillation used to separate?

  Two liquids with different boiling points
• How does fractional distillation work?

  • Liquids evaporate and climb up the fractional distillation column
  • Different liquids will condense out at different temperatures as they travel up the column
• How does simple distillation work?

  • Heat the solution until the substance with the lowest boiling point evaporates into a vapour.
  • The vapour passes through the condenser, cools and condenses into a liquid. The liquid collects in a beaker.
• What separation technique would you use to separate out

  different inks in pens?

  Chromatography
• How can salt be collected using the process of crystallisation?

  By heating up a mixture of salt and water, the water will

  evaporate and leave the salt in the bowl.
• Sand and water can be separated by using a process called?

  Filtration
• Describe, in 4 steps, how to collect salt from rock salt.

  1. Grind the mixture
  2. Add water and salt
  3. Filter the mixture
  4. Evaporate the salt water and salt is left over