Flame Test
Purpose: To identify metal ions using the flame test and to determine the identity of an unknown
Introduction: Compounds of several common metal cations give distinct color to a flame. Therefore, a
flame test is often used as a confirmatory test in the identification of an unknown metal. Compounds of
these ions provide the beautiful colors in fireworks displays.
Materials:
Methanol
Sodium nitrate
Barium nitrate
Lithium nitrate
Copper nitrate
Safety equipment
Potassium nitrate
Calcium nitrate
Strontium nitrate
50mL beaker
Bunsen burner
Striker
Q-Tips
100 mL beaker
Pre-Lab Questions (15 points)
1. Discuss the safety hazards involved with this lab
2. Why do we dip the Q-Tip in the methanol first, before the salts?
3. If you had three unlabeled bottles, and you know that one is sodium nitrate, one is strontium
nitrate, and one is calcium nitrate, how could you determine the identity of the contents of each
bottle?
Procedure: (10-15 minutes)
GOGGLES MUST STAY ON DURING THE ENTIRE PROCEDURE!
1. Obtain lab equipment
2. Place the Q-Tip n the methanol and then in the sodium chloride. Check to see if some of the salt
is on the Q-Tip.
3. Burn the salt. Record the color in the data table.
4. Drop the Q-Tip in a 100mL beaker of water.
5. Obtain a clean Q-Tip, dip in methanol
6. Burn the other salts using the same method and record their color in the data table.
7. Burn the unknown salt and identify the mixture
Data Table: Create your own data table on the back of this page.
Post –Lab Questions: (15 Points)
1. What are your testing, the metal or the nitrate?
2. What is a practical use for the flame test?
3. Discuss an occupation that can use such methods of determination.
Extension: (15 points)
Assume that the following colors correspond to the listed wavelengths. Violet – 400nm, Blue – 450nm,
Green – 500nm, Yellow – 570nm, Orange – 650nm, Red-orange – 680nm, Red – 750nm. Calculate
frequency and energy of the light emitted by each trial. Record your results in a data table.