Observing The Flame Colour

Perform first-hand investigations to observe the flame colour of Na+, K+, Ca2+, Ba2+, Sr2+, and Cu2+

Objective: To observe colours produced by excitation of metal ions through heating


  1. Use a pipette to place a drop of metal nitrate solution in clean wire loop
  2. Suspend the drop of solution at the edge of blue flame of Bunsen burner
  3. Record the observed flame colour
  4. Use a spectroscope or diffraction grating to observe for the colour of flames
  5. Record the flame colour observations


  • Repeat experiment at least 5 times or until three sets of consistent results are achieved


  • The use of spectroscope and diffraction grating allow more precise quantitative data to be gathered


  • Control: Use same concentration of solution, identical anion, same heat source and fuel, same Bunsen flame colour