Title - The Bunsen Burner
Introduction - Bunsen and Kirchoff were spectroscopists, scientists who analyze the spectra emitted from samples placed
in a flame. Bunsen and Kirchoff developed a burner and a system of lenses, which included a prism. This optical system
was capable of identifying the characteristic spectra of individual elements. This led to the discovery of two new
elements, cesium and rubidium. The Bunsen burner is designed to burn propane gas (C3H8) in a combustion reaction. The
propane reacts with oxygen in the air to form carbon dioxide and water and a great deal of heat energy.
Purpose: 1. Become familiar with the parts of a Bunsen burner.
2. Become proficient in igniting and extinguishing a Bunsen burner.
3. Distinguish between the two main types of flames that are produced by a Bunsen burner.
4. Demonstrate the proper safety skills associated with using a Bunsen burner.
Terms to Know: Bunsen burner, luminous flame, non-luminous flame
Materials: Bunsen burner, striker, test tube, test tube holder
Procedure Follow the steps outlined below. Fill in the data table as you complete each step.
1. Following your summary of procedure, leave about 1/3 of a page for a sketch the Bunsen burner. Label
the gas inlet nozzle, air vents, turn valve, barrel, hose & desk jet. Briefly, note the function of each.
2. Close the turn valve completely by turning it counterclockwise (when looking down on the Bunsen
burner as it rests on the lab bench) until it is finger tight. Adjust the barrel so the air vent is "just" open
(about one turn). Attach the gas hose to the desk jet and to the gas inlet nozzle. Be sure the burner base is
flat on the table.
3. If you are using a striker instead of a match try it out. You must be able to produce a spark in order to
light the burner.
4. Note the off/on positions of the desk jet. Open the desk jet completely. The handle will be directly over
the nozzle when opened, perpendicular to the nozzle when closed.
5. Open the turn valve by a few turns. Make a spark near the rim of the barrel. If using a match, hold the lit
match to the side of the top of the barrel. The burner is lit.
6. Close the barrel by turning it clockwise. Note the color, shape, and movement (if any) of the
flame. This is called a luminous flame. This type of flame is rarely used in lab.
7. Adjust the flame by turning the barrel clockwise, thus opening the air vents slowly until you have a pale
blue flame. Note the color, shape, and movement of the flame. This is warm flame and will sometimes
be used in lab.
8. Continue to adjust the flame by further opening the air vents slowly until you have a pale blue flame with
a bright blue center an "inner cone". Note the color, shape, and movement of the flame. This is called a
non-luminous flame. This type of flame is frequently used in lab. It is a very hot burning flame.
9. Draw this cone within a cone flame above the barrel on your drawing of the Bunsen burner. Label the
oxidizing and reducing zones of this non-luminous flame. Also, draw an arrow to the hottest point in the
flame and label it “hottest point”.
10 Continue to open the barrel until the air vents are wide open. Record your observations. When too much
oxygen is introduced to the gas mix, the flame is unstable.
11. Adjust the barrel to get the inner cone back. Continue to increase the gas pressure by opening the needle
valve. Record your observations.
12. Turn off the burner by shutting off the gas at the desk jet. Then close the turn valve (which is connected
to the interior needle valve). Have your partner go through the steps to relight the burner correctly.
13. With the air vents of the burner closed, hold a glass tube with the test tube clamp in the flame for a short
time. A deposit will soon appear on the tube. Remove the test tube when the deposit has appeared and
examine it. What is the deposit called? What element is this deposit made of? Open the air vents and
again hold the blackened tube in the flame? What becomes of the deposit?
14. Let the test tube air cool on the lab bench. When cool was the test tube. Put all your materials away
when they are cool.
Observation Table 1
air (oxygen) flow
color shape sound ( too high, ideal-high,,
medium, or low)
Flame with barrel
Flame with barrel
Flame with inner
Flame with barrel
Observation Table 2 Surface of Test Tube
Bunsen Burner with
air vents closed
Bunsen Burner with
air vents open
1. What is a common name for the deposit made on the test tube when the Bunsen Burner had its air vents
2. What element is the deposit made of?
3. What happens to this deposit when a non-luminous flame heats the test tube?
4. The type of chemical reaction involve in burning the gas is called combustion. Is this an endothermic or
5. Since combustion results in the production of carbon dioxide gas (CO2) and water vapor, then explain
the production of the black solid on the test tube.
6. What does the black solid become as it is exposed to the tremendous heat from the non-luminous flame?
(hint: refer to question 5)
Discuss the safety issues involved with working with the Bunsen burner. Address all possible concerns
including but not limited to hair, clothing and inspection of equipment. Also, report what type of safety plan
you should use in case of an emergency involving the Bunsen burner and fire in your classroom.