Lab – Effect of Oxygen on Combustion of Ethyne
Purpose: To determine the effect of differing amounts of oxygen on the combustion of ethyne
( acetylene).
Hypothesis: The tube with _____________% of ethyne will show complete combustion. Other tubes
with less oxygen will show ____________________________ combustion. (2)
Prelab:
a) Write out and balance the equation for the reaction of ethyne ( C2H2)with oxygen. (2)
b) Write out and balance the reaction of calcium carbide with water. (2)
Materials: list all materials used – be specific and draw a fully labeled diagram of the experimental
set-up. (6)
Procedure:
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Put on goggles, tie back hair, push in stools and clear aisles before beginning.
Obtain three tubes of ethyne gas- a) 100% ethyne, b) 50% ethyne and c) 10% ethyne.
Clamp a test tube clamp to a retort stand.
Clamp test tube A to the retort stand making sure it is secure and is pointing away from
yourself. Place a blast shield between your group and the lab materials.
Reach around the blast shield and remove the stopper from the tube and quickly bring a
burning splint to the mouth of the tube. Observe the combustion.
Clean tube after it cools and wash and dry it.
Repeat steps 4-6 with test tube B then test tube C.
Clean up all materials.
Observations:
Describe each reaction and the visible products produced. (put observations into short
paragraphs. (6)
Discussion Questions :
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What are the dangers of incomplete combustion? ( give at least two and explain each) (4)
What are some uses of ethyne? ( give two minimum) (2)
How does CO2 from combustion affect the atmosphere and ocean pH? (4)
How would a clogged air filter affect the operation of a car? (3)
Explain why the balanced equation for the combustion of ethyne will not give you the correct
proportions of air and ethyne needed for complete combustion. (2)