Tests for cations

• Flame test:

  • Lithium = Crimson red
  • Sodium = Yellow
  • Potassium = Lilac
  • Copper = Green
  • Calcium = Red
• 1. Clean a nichrome wire loop by dipping it into hydrochloric acid and then rinsing it in deionised water.
  2. Then dip the loop into the sample of the metal compound
  3. Put the now dipped loop into the blue flame of the bunsen burner, and record the colour
• Some metals form a coloured precipitate with Sodium Hydroxide (NaOH):

  • Add a few drops of NaOH to your mystery compound
  • Record the colour of the precipitate formed
• Sodium hydroxide precipitates

  • Calcium = White
  • Copper = Blue
  • Iron (II) = Green
  • Iron (III) = Brown
  • Zinc = White, before dissolving to be colourless