Appendix B
Methane Bubble Demonstration
(modified from Flinn Scientific "Chem Fax: Methane Bubbles")
Materials:
1 meter stick with candle attached at one end
1 match or lighter
3-4 meters of rubber tubing
1 funnel
120 mL liquid dishwashing soap
800 mL water
1 small bucket or container
methane gas line
Safety:
1. Wear heat resistant apron and goggles.
2. The methane bubble formed should not be more than 4-5 inches in diameter. Larger bubbles can be dangerous.
3. Do not light the bubbles near light bulbs or smoke detectors.
4. Have a fire extinguisher ready in case of an accident.
Preparing for the demonstration:
1. Take the rubber tubing and connect one end to the gas line and the other end to the funnel.
2. Add 120 mL of dishwashing soap to the small bucket and add 800 mL of water.
Procedures for the demonstration
1. Place the funnel into the soapy water so that a soap film appears on the opening of the funnel.
2. Open the methane gas line to fill the funnel with methane gas. A bubble will appear at the end of the funnel.
3. Shake the bubble off of the funnel with a gentle flick of the wrist.
4. The bubble will begin to rise to the ceiling. As the bubble is suspended in the air, touch the lit candle to the bubble and observe the large flame.
Tips:
1. Always practice demos before demonstrating it in the classroom.
2. This demonstration is difficult to do alone. Procedure steps 1-3 can be done by a volunteer student but the lit candle should be handled by the teacher.
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