Salt preparation

• Salt


  A metal compound formed when an acid reacts with a metal, a base or a metal carbonate
• Precipitate


  A solid formed on mixing two solutions
• Precipitation

  A reaction in which a solid forms on mixing two solutions
• Base


  A metal oxide or hydroxide e.g. copper oxide, sodium hydroxide etc.
• Flame test results


  • Raising/effervescence
  • White precipitate
  • Blue-green
  • Yellow/orange
  • Lilac
  • Crimson
  • Brick red
  • Bubble gas produced through limewater, limewater changes from colourless to cloudy white
  • Squeaky pop
• Naming salts


  The first part of the name of the salt comes from the metal ion present. The second part comes from the acid from which it is made.
• Reactions that make salts


  1. Reaction of metals with acid

  2. Reactions with alkalis/bases

  3. Reactions with metal carbonates
• Reaction of metals with acid: METAL + ACID → SALT + HYDROGEN
• Reactions with alkalis/bases: BASE + ACID → SALT + WATER
• Reactions with metal carbonates: METAL CARBONATE + ACID → SALT + WATER + CARBON DIOXIDE
• Overview of Method for Making Soluble Salt


  1. Add reactants to beaker

  2. Filter off unreacted solid

  3. Evaporate 2/3 of the water

  4. Cool to crystallise salt

  5. Dry using low temperature oven
• Excess copper carbonate is added to use up all of the sulfuric acid
• Word equation for copper carbonate and sulfuric acid reaction


  1. Copper Carbonate

  2. Sulfuric acid

  3. Carbon dioxide

  4. Water

  5. Copper sulfate
• If all the water is evaporated, a white solid would be produced as water is an important part needed to make the blue crystals
• Hydrochloric acid


  Hydrogen & chloride
• Flame test


  Identify the metal ion in the salt
• To make a solution of the salt, deionised water should be used
• Specific colours


  • Copper carbonate-green
  • Copper sulfate/chloride/nitrate-blue solution, blue crystals
  • Copper oxide-black powder
  • Everything else is either a white solid or a colourless solution