Making salts: Chemical Changes: Chemistry: GCSE (9:1)

• Filtration

  Separates insoluble solid from a liquid

  
• Crystallisation


  The formation of crystals (as solvent evaporates from solution)

  
• Filtrate


  Liquid that has passed through a filter

  
• Residue

  The insoluble solid left in the filter paper

  
• Advantage of heating a reaction

  Speeds the reaction up
• Making salt from acid+base

  Reacting an excess of insoluble base with an acid, filter off excess base
• Making a salt from acid+metal

  React an excess of metal with an acid, filter off excess metal
• Making salt from acid+alkali

  Use titration with an indicator to find the amount alkali to neutralise the acid, repeat without indicator to make a pure sample

  
• Making pure dry crystals

  Crystallisation then pat crystals dry between two pieces of filter paper
• Advantage of a water bath

  Heats gently, allowing water to evaporate slowly
• Indicator


  A compound that changes color in the presence of an acid or a base
• Pipette


  A glass or plastic tube used to accurately measure liquid

  
• Burette


  A graduated glass tube with a tap at one end, for delivering known volumes of a liquid