Names:
Bunsen Burner Lab
PURPOSE: To show the proper technique of lighting and adjusting the Bunsen Burner. Regions of combustion
and variations in temperature are observed.
MATERIALS: Bunsen burner w/gas supply, matches, burner square, tongs
Methane is the natural gas used in most labs. Sufficient oxygen is needed for complete combustion. The
combustion of methane produces a blue non-luminous flame producing carbon dioxide and water. When the
oxygen supply is insufficient, small carbon particles are produced that form a yellow luminous flame. Bunsen
burners were designed to produce a combustible gas-air mixture that produces an efficient, hot flame. A
properly adjusted burner flame should have three distinct cones: an outer violet oxidizing flame and an inner
blue reducing flame with a cone of unburned gas. The tip of the blue cone is the hottest part of the flame-
reaching 15000C. The cool region outside the blue cone may only be 3000C.
PROCEDURE:
Safety Precautions: This lab requires you to use caution - you need to tie back long hair and roll up long
sleeves. Do not touch the barrel of the burner because it gets very hot. Always use tongs when handling hot
items in this lab. Also, remember to always turn off the gas when you are finished.
1. Connect burner to a gas outlet. Turn on the gas and bring a lighted match directly into the area at
the top of the barrel. Good gas pressure will blow the match out.
2. Light a second match and bring it slowly over the edge of the barrel from the side. What happens?
3. Using tongs, hold a wire gauze square horizontally about 3 cm above the unlit burner. Turn on the gas
and light the burner below the screen and wait for a short period of time. Observe. Move the screen up
and down in the flame and observe. What happens?
4. When you change the position of the metal collar on the air hole, the color of the flame changes.
a What is the color of the flame when the air hole is fully open?__________________________
b What is the color of the flame when the air hole is fully closed?___________________________
c What is the color of the flame when the air hole is half open?_____________________________
d Which of these flames is the hottest flame?_____________________________
5. Turn off the gas supply. Put any used matches in a safe location (determined by your teacher.)
