Summary: Bubbles filled with methane rise when released. The rising bubbles are set on fire with a candle on a stick to demonstrate the combustion reaction.
Hazards:
Methane gas is flammable.
Chemicals and Solutions:
Bubble Solution
Methane source
Materials:
Glass funnel with long stem
Large crystallizing dish
Long stick with candle attached
Matches
Methane gas outlet
2-3 feet of amber tubing
Procedure:
Place the soap solution in the crystallizing dish.
Attach one end of the tubing to the gas outlet and the other end to the stem of a funnel.
Place the mouth of the funnel into the soap solution.
Light the candle and hold the stick in one hand.
With the other hand, turn the gas on low such that bubbles form slowly.
Once the inside of the funnel is coated with soap, remove the funnel from the soap solution and hold it such that the mouth points upward. Once you have a large bubble, shake it loose from the funnel. As the bubble rises, try to ignite it with the candle.
Hint: Be careful to release the bubbles before lighting, or the funnel will catch fire. If the funnel does catch fire, turn off the methane to extinguish.
Discussion:
Disposal:
The soap solution can be reused.
To schedule a demonstration, please send an email to the demonstration lab.
Contact:
Eric Camp
Lecture Demonstration Technician
Bagley Hall 171
(206) 543-1606