Tests for ions

Cards (4)

  • How can you detect carbonate ions and hydrogen carbonate ions?
    • in dilute HCl both will fizz and give off CO2
    • you can bubble the CO2 in limewater and if it goes cloudy CO2 is present.
    • If it goes cloudy the carbonate or hydrogen carbonate ions have been identified
  • How do you test for sulfates?
    • Add dilute HCl and follow it with barium chloride solution. If a white precipitate forms, the original compound contained sulfate.
  • What can you use to test for ammonium compounds?
    ammonia gas is an alkaline, so you can test for it using damp red litmus paper.
    If it goes blue ammonia is present.
  • For substances containing ammonium ions:
    • Add some sodium hydroxide to the substance and gently heat it
    • If ammonia is given off, ammonium ions are present