test for anions

• • carbonates react with dilute acids to form carbon dioxide and water
  • to test if carbonate ions are present, carbon dioxide can be identified with limewater
• • sulfate ions reacts with dilute hydrochloric acid and barium chloride to form a white precipitate of barium sulfate
  • hydrochloric acid is added to remove any carbonate ions
• • halide ions react with silver nitrate solution in the presence of dilute nitric acid to form precipitates
  • chlorides form a white precipate of silver chloride
  • bromides form a cream precipitate of silver bromide
  • iodides form a yellow precipitate of silver iodide