Tests for anions

• What is the first step in testing for anions?

  Add dilute nitric acid
• What is the purpose of adding silver nitrate in the test for halide ions?

  To form a precipitate with halides
• What are the colors of precipitates formed with different halide ions?

  • Chloride: White
  • Bromide: Cream
  • Iodide: Yellow
• What color precipitate is formed with chloride ions?

  White
• What color precipitate is formed with bromide ions?

  Cream
• What color precipitate is formed with iodide ions?

  Yellow
• How do you test for carbonate ions?

  Add dilute HCl and collect gas
• What indicates the presence of carbonate ions in a test?

  Gas bubbles turn lime water cloudy
• How do you test for sulphate ions?

  Add dilute HCl and Barium chloride
• What is the result of a positive test for sulphate ions?

  A white precipitate forms
• What are the steps to test for carbonate ions?

  1. Add dilute HCl to the sample.
  2. Collect the gas produced.
  3. Bubble the gas through lime water.
  4. Observe if lime water turns cloudy.
• What are the steps to test for sulphate ions?

  1. Add dilute HCl to the sample.
  2. Add Barium chloride to the mixture.
  3. Observe if a white precipitate forms.