Laboratory Experiment: Flame Test

Question: When a compound is placed in the flame of a burner, what. happens to the color of the flame and what causes this to occur?

When chemical compoundsare heated, they gain energy. The electrons insome of these chemicals will jump from their ground state electronconfiguration (such as the electron configurations we have been drawing forthe elements) to higher energy levels. As these electrons fall back to theiroriginal positions in the atom, they emit energy. One form of this energy islight energy. This is what you will be observing in this experiment.

Materials required:

Nichrome wire wandTest tubes containing waterTest tubes containing 6M hydrochloric acid as needed to clean wireTest tubes containing:

Copper sulfatePotassium sulfateCopper nitratePotassium nitrateStrontium nitrateCalciumnitrateCopper chloridePotassium chlorideStrontium chlorideCalciumchlorideCobalt chlorideSodium chlorideSodium nitrateSodium sulfateBarium chlorideCalciumnitrate

Ti rrel burnerMatchesGogglesApron

ProceduresSafety: Wear goggles at all times. If you want to remove them to write inyour notebook you may sit at a table in the center of the room. When yousit down remove them and when you stand up put them on. Use aprons. Pull .back hair. No loose clothing. Close-toed shoes. NO FOOLING AROUNDIt is very important that you DO NOT mix up the nichrome wire wands.

Watch Demo before you begin

9. When you table is done with both chemical compounds, pass them bothclockwise to the next table.

1. Work in teams of two

2. At each table there are two samples and two tirrel burners and matches.Start the burner as you have learned to do and obtain a low blue flame withthe inner blue flame.

3. Next take the nichrome wire and place in the flame. Notice its colorwhen it becomes red hot. This is not the color of the flame you are lookingfor. The flame to observe is the one obtained just as you place it in theflame.

4. Place the wand in the test tube with the solution of the compound, quicklyplace it in the flame and observe its color. Write down the color and anyobservations on the table provided below. Do this no more than three times.

5. Then rinse the wire in the water

6, Heat the wire in the flame until it has no residue from the compound left.If you have problems ask your teacher.

7. Return the nichrome wire to the water test tube. When this iscompleted, exchange chemical compound setups with you tablemates.

8. Repeat the procedure for each chemical compound.

10. When all chemical setups are complete, the class will discuss whichchemical compounds that you would like to observe again.Flame Test Data - Table 1

Color&Shape ObservationCompound