Testing Anions

• Carbonate ions:

  • add dilute hydrochloric acid
  • bubble gas produced through limewater

  Result:

  limewater turns cloudy
• Sulfate ions:

  • add dilute hydrochloric acid
  • This removes any carbonate or sulfide ions, which are impurities
  • Add barium chloride solution

  Result:

  • white precipitate
• Halide ions (chloride, bromide and iodide):

  • Add dilute nitric acid
  • Removes carbonate and sulfide impurities
  • Add silver nitrate

  Results:

  Chloride ions - white precipitate

  Bromide ions - cream precipitate

  Iodide ions - yellow precipitate