Tests for negative ions

Tests for negative ions

1. Carbonate ions

   • Add dilute hydrochloric acid to the substance to see if it fizzes. If it does and the gas turns limewater milky, the substance contains carbonate ions.

2. Halide ions

   • Add dilute nitric acid and then silver nitrate solution
     • Chloride ions: White precipitate
     • Bromide ions: Cream precipitate
     • Iodide ions: Yellow precipitate

3. Sulfate ions

   • Add dilute hydrochloric acid and then barium chloride solution.
     • If a white precipitate forms, sulfate ions are present.