Name ______________________
Flame Test Lab Date _______________________
Hour __________
Purpose: to observe and identify metallic ions using flame tests.
Background
Have you ever wondered why a candle flame is yellow? The characteristic
yellow of a candle flame comes from the glow of burning carbon fragments. The carbon
fragments rare produced by the incomplete combustion of the wick and candle wax.
When elements, such as carbon, are heated to high temperatures, some of their electrons
are excited to higher energy levels. When these excited electrons fall back to lower
energy levels, they release excess energy in packages of light called photons, or light
quanta. The color of the emitted light depends on its energy. Blue light is more energetic
than red light, for example. When heated, each element emits a characteristic pattern of
light energies, which is useful for identifying the element. The characteristic colors of
light produced when substances are heated in the flame of a gas burner are the basis of
flame tests for several elements.
In this experiment, you will perform the flame tests used to identify several
metallic elements.
Safety
The metal salts you will be using in this lab are poisonous. Avoid skin contact with these
chemicals.
You will be using fire so tie back long hair and restrain loose clothing.
Wear goggles.
Materials:
Soaked wooden splints
Potassium nitrate
Calcium nitrate
Strontium nitrate
Lithium nitrate
Copper (II) nitrate
Sodium nitrate
Barium nitrate
Cobalt glass
Procedure
1. Obtain a set of metal salts and several soaked wooden splints.
2. Light and adjust a lab burner until you have a blue flame.
3. Taking one salt vial at time follow this procedure:
a. Take a clean wooden splint and dip into the metal salt container to adhere
a few crystals of the salt.
b. Place the end of the wooden splint with the salt in to the burner flame.
c. Observe any color produced and record that in your data table.
d. Remove the wooden splint from the flame (wet to extinguish if necessary).
e. Place the used wooden splint into the match disposal can.
4. Repeat step 3 again with the sodium and potassium nitrate salts, this time viewing
the color emitted through the cobalt glass.
