Flame Tests
The photographs show the emission or color of light from different metal ions. Wooden sticks were soaked in ionic solutions: sodium chloride, lithium chloride, copper chloride, and strontium chloride. The first picture is of the methane burning, followed by a wooden stick burning and then the ions of sodium, lithium, copper, and strontium.
Description
Cations can be identified by characteristic colors, when a compound containing the cation is heated in a burner flame. The purpose of this demonstration is to show the colors and to associate them with the cation in the compound.
Note: All the anions are the same (chloride) and do not give a color.
Materials
Use samples of BaCl2, CaCl2, CuCl2, SrCl2, NaCl, KCl
Procedure
Soak wooden sticks in 1 M solutions of each salt overnight.
Hold stick over Bunsen burner flame and observe color.
Remarks
For reference, expected colors of the cations used in this demonstration follow.
Ba2+ greenish-yellow Ca2+ brick-red Cu2+ green Sr2+ crimson Na1+ yellow K1+ Violet