LEDERMANN Name Hour Flame Tests Lab Introduction: Elements can be identified by the color of light they give off when their atoms release absorbed energy. This is the basis for a simple analytical method called a flame test, which was perfected by Robert Bunsen. In this lab, you will observe and record the colors of several metals and then use this information to identify unknown samples. (This is the principle used in designing fireworks.) Procedure: You must wear goggles during this experiment! Be sure the flame on your bunsen burner is blue before beginning. Wooden splints have been soaked in several solutions. Take a wooden splint and put it in the flame of your bunsen burner. Record the color you observe. After you have completed the known solutions, obtain two unknowns and repeat the procedure. Try to identify the unknowns. Shut the gas off completely, clean your station, and wash your hands when you are finished. Data: Compound Description of Flame Color Lithium chloride (LiCl) _____________________________ Strontium chloride (SrCl2) _____________________________ Calcium chloride (CaCl2) _____________________________ Barium chloride (BaCl2) _____________________________ Copper (II) chloride (CuCl2) _____________________________ Sodium chloride (NaCl) _____________________________ Potassium chloride (KCl) _____________________________ Cobalt (II) chloride Unknown # _______ color_____________ I believe this is ______________________ Unknown # _______ color_____________ I believe this is ______________________ Questions: 1. Is flame color test for the metal or the chloride ion?________________ How do you know? 2. Why would sodium chloride and sodium nitrate have the same color of flame? 3. The color you see depends on the amount of ____________that the electrons lose. (over) 1. Draw Bohr model diagrams for the following. Correctly place the proper number of electrons 2. Draw a Bohr diagram below for Potassium (K). Put the correct number of protons and neutrons in the nucleus. (Do not make the nucleus a solid color!) Then add the electrons. .