Specification Point 2.48:
Describe tests for these anions: Cl, Br and I using Acidified Silver Nitrate Solution, SO42- using Acidified Barium Chloride Solution, CO32- using Hydrochloric Acid and identifying the gas evolved

Anions: A negatively charged ion.

Test for Cl, Br and I

Test for Chloride, Bromide and Iodide, Edexcel IGCSE Chemistry

The test for Cl, Br and I

Method:

  • Add some dilute Nitric Acid to react and remove carbonate ions
  • Add a few drops of Silver Nitrate solution
  • Colour of precipitate is observed and recorded
  • Precipitate is silver halide compound.

Result and Equation:

Chloride, Bromide, Iodide Table, Edexcel IGCSE Chemistry

Test for SO42-

The test for Sulfate Ions

Method:

  • Add some dilute Hydrochloric Acid to react and remove carbonate ions
  • Add a few drops of Barium Chloride solution
  • Colour of precipitate is observed and recorded

Result:

  • If sulfate ions are present, a white precipitate will form (Barium Sulfate)

Equation:

  Ba2+ (aq)      +         SO42-  (aq)       →           BaSO4 (s)             

Test for CO32-

The test for Carbonate Ions

Method:

  • Add dilute Hydrochloric Acid
  • Bubble the gas produced into limewater
  • Colour of precipitate is observed and recorded

Result:

  • If carbonate ions are present, carbon dioxide is produced when reacted with hydrochloric acid.
  • Carbon dioxide reacts with limewater to turn milky.

Equation:

CO32- (aq)      +         2H+  (aq)      →       CO2 (g)       +       H2O  (l)      

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Author: Jamie

Jamie got a First class degree in Chemistry from Oxford University before going on to teach chemistry full time as a professional tutor. He’s put together these handy revision notes to match the Edexcel IGCSE Chemistry specification so you can learn exactly what you need to know for your exams.