Making soluble salts

• Salt

  A compound containing a positive ion (metal ion) and a negative ion (from an acid)
• Sources of metal ions for salts

  • Metal
  • Metal oxide
  • Metal hydroxide
  • Metal carbonate
• Making a soluble salt using a metal oxide and acid

  1. Use dilute sulfuric acid as the limiting reactant

  2. Gently heat the acid

  3. Add small amounts of metal oxide and stir

  4. Stop adding oxide when solution is blue

  5. Filter out any unreacted oxide

  6. Evaporate solution to form crystals

  7. Allow crystals to form over 24 hours

  8. Dry the crystals
• Copper is not reactive enough to make copper sulfate by reacting with dilute sulfuric acid
• The solution turns blue when the copper sulfate is formed
• The reaction stops when all the acid has reacted
• Filtering removes any unreacted copper oxide, which is insoluble