Neutralisation

• when metal oxides and hydroxides react with acid they always form a salt + water
• You always take the negative ion from the acid and add it to the positive ion from the base to form a salt when reacting metal oxides/hydroxides with acid.
• Acid + Metal Carbonates --> Salt + Water + Carbon Dioxide
• Salts formed from oxides, hydroxides and carbonates are soluble in water. Sp to make a soluble salt react an acid with a soluble base.
• Method of neutralisation

  • Place dilute acid in a beaker
  • Gently heat with a bunsen burner
  • Keep adding the insoluble base a little bit at a time
  • At first, it will keep disappearing as it reacts to form a salt and water
  • As you add more some of the base will stop disappearing
  • At this point you know the bae must be in excess and you have neutralised all of the acid
  • Filter out all excess base using filter paper and funnel
  • Now you are left with dissolved soluble salt and water
• To form solid crystals of soluble salt

  • Gently heat dissolved soluble salt and water using a water bath or electric heater
  • So we don't risk damaging our salt
  • Evaporate off some water
  • Once crystals begin to form stop heating
  • Leave it to cool
  • Filter the crystals out with filter paper and funnel
  • Dry them by dabbing with filter paper, or leaving somewhere warm.