From: ROY MAYEDA (roymayeda@yahoo.com)
Date: Mon Aug 25 2003 - 21:08:45 PDT
Message-ID: <20030826040845.27717.qmail@web20414.mail.yahoo.com> Date: Mon, 25 Aug 2003 21:08:45 -0700 (PDT) From: ROY MAYEDA <roymayeda@yahoo.com> Subject: Re: first day ideas
The demo described is commonly referred to as the "Whoosh Bottle" demonstration. I was not aware of this demo (or the hazards associated) with it until a year or so ago. The topic came up on the AP Chemistry listserve. There have been many confirmed incidents of the bottle EXPLODING and spraying the room with glass shards if a glass bottle is used. An instructor at my last school in MN who had "done this for years" had his detonate at the end of the 2002 school year. Fortunately, the instructor received only minor injuries, and no students were injured. DO NOT perform this demo with a glass water bottle (the old water cooler bottles). It is recommended that if you choose to do this, use a PLASTIC bottle, wrap it in layers of clear packing tape, and replace the bottle periodically. (The plastic also eventually fatigues and becomes brittle.) Methanol was also recommended (I believe no more than a few mL's) as the alcohol. Flinn Scientific also describes a replacement demo
using a long thick-walled tube to replace the bottle.
You might also try the "California Snow" demo. I'd have to look it up (and all of my books are in a semi-trailer right now!) but I think it was calcium acetate (?) and ethanol. You get a colloid (basically Sterno) and can light it and "play" with a ball of it if you keep your hands moistened with cool water.
Roy Mayeda
(Still looking for a job in western MN -- no, I can't grow corn, soybeans, or sugar beets!)
:-)
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