The Generations Symposium is a special event at ChemEd in which teachers new to classroom work with mentor teachers to present chemistry demonstrations, resulting in a series of five-minute presentations totaling two hours. Micaela Ferreira is a new teacher at my school and together we were fortunate to have the opportunity to participate in Generations at ChemEd 2013. We presented the Singing Flame Tube demo. This demo is a nice (and safer) variation of the classic Whoosh Bottle demo. I first saw this demo at a Flinn presentation at NSTA in Boston.I have an 8-foot polycarbonate tube that's about 3.5" in diameter, which I had originally obtained from US Plastics Corp. I drove this tube 840 km — all the way from Pomfret, Connecticut to Waterloo, Ontario. It was totally worth it.
For our demo, you first stopper the tube’s one end, then pour about 50 mL of rubbing alcohol in the tube. Next you stopper the other end, and twirl the tube for a few minutes to distribute the alcohol evenly as well as to vaporize some of it. Here's the most important step: you must drain out the excess alcohol into a beaker. Once you've drained the excess liquid, you hold the unstoppered (remove stopper from both ends), alcohol-charged tube over a candle. The tube sometimes will pulse and make a sound like an organ. It often goes quickly, but if you're lucky (and the tube is warm) it will pulse and give a longer burn. Usually the second or third time is better than the first. A protective glove protects the hand from the heat generated inside the tube.