Flame Test Lab

Name: ______Date: ______

Purpose: To gain an understanding of the characteristic colors emitted by elements when their electrons are excited, and to identify an unknown element.

Materials: water-soaked wooden splints, samples of metal ions, Bunsen burner

Procedure: 1. Put on your goggles, and obtain all necessary materials. 2. Light your Bunsen burner and make sure that the flame is not too tall. 3. Dip just the tip of a clean splint in to a metal powder and then hold the splint in the hottest part of the flame. Observe the color of the flame and record it in the data table below. 4. Discard the used splint. 5. Repeat steps 3 and 4 for each of the remaining metal powders provided. Be sure use a new splint for each metal. 6. Turn off the Bunsen burner and clean up your area.

Metal Ion Flame Color Sodium (Na+)

Barium (Ba+)

Calcium (Ca+)

Copper (Cu+)

Potassium (K+)

Strontium (Sr+)

Lithium (Li+)

Unknown Conclusion Questions :

1. Which elements had very similar flame colors? Discuss how this fact is related to their position on the periodic table.

2. What part of the atom gains energy from the flame and then loses it in the form of light?

3. Which of the samples emitted light that could have a frequency of 5.85 x 1014 Hz? What would the wavelength of that light be?

4. Identify your unknown and state how you arrived at that conclusion.

5. Flame tests are sometimes invalid. Why might this be?

6. A kitchen worker at a local hospital was filling salt shakers. For those patients on a sodium restricted diet due to high blood pressure, the hospital provided a salt substitute containing potassium chloride instead of sodium chloride. Unfortunately, the hospital worker mixed some of the containers up. How could the contents of the containers be identified?