more seperation techniques

• How to do Evaporation:

  
  

  1. Pour the solution into an evaporating dish

  2. Slowly heat the solution. The solvent will evaporate and the solution will get more concentrated. Eventually, crystals will start to form

  3. Keep heating the evaporating dish until all you have left are dry crystals
• Evaporation


  • A really quick way of separating a soluble salt from a solution
  • Can only be used if the salt doesn't decompose (break down) when heated
• How to do Crystallisation:

  
  

  1. Pour the solution into an evaporating dish and gently heat the solution. Some of the solvent will evaporate and the solution will get more concentrated

  2. Once some of the solvent has evaporated, or when you see crystals start to form (the point of crystallisation), remove the dish from the heat and leave the solution to cool

  3. The salt should start to form crystals as it becomes insoluble in the cold, highly concentrated solution

  4. Filter the crystals out of the solution, and leave them in a warm place to dry or drying oven or desiccator
• Rock salt is a Mixture of salt and sand
• Salt and sand are both compounds
• Salt Dissolves in water
• Sand Does not dissolve in water
• Separating salt and sand


  1. Grind the mixture to make salt crystals small so dissolve easily

  2. Put mixture in water and stir, the salt dissolves but sand doesn't

  3. Filter the mixture, grains of sand collects on paper, salt passes through as its part of the solution

  4. Evaporate water from salt so that it forms dry crystals
• Filtration can be used to purify a reaction mixture by separating out solid impurities