Date: Sun, 15 Aug 2010 00:32:55

Author: Urs Lauterburg

Subject: Re: H2 bangs and soap solution

Post:

I have blown up at a 2:1 ratio of hydrogen/oxygen filled ballons on
several occasions. The ignition was achieved with a burning candle on
a long stick. It does make big bangs. Once the shock wave even made a
lamp housing fall off the auditorium's ceiling, so I made the
following ballons smaller in size. I fortunately never experienced a
spontaneous ignition though. It does feel a bit itchy when filling in
the gases from the pressurized flasks with the valves and when
closing the ni@pple of the balloon. Now, with Dale's experience I
will even feel less at ease..

In the case I would have to show this at some place other than our
demonstration facility I would certainly take the flasks with me and
fill the balloons right on site. Well not in front of the crowd of
course but shortly before showing it. I have observed that the gas
mixture escapes relatively fast through the balloons thin rubber
foil. I assume hydrogen to go out much quicker than the oxygen.

Urs

Urs Lauterburg
Physics demonstrator
Physikalisches Institut
University of Bern
Switzerland

>On Thu, 12 Aug 2010, David Maiullo wrote:
>
>>Anyone else ever have a spontaneous explosion of H or H & O balloons?
>
>I've never dared mess with this myself, but hobbyists report that it
>happens all the time: the slightest electrostatic discharge is
>extremely dangerous. The (partial?) cure is soapy water inside so
>it coats rather than beading up. But I've also heard about one
>spontaneous explosion inside a closed acrylic electrolysis cell.
>
>I first heard about this around 1992 from a story of crazed
>teenagers setting off a packed row of five (seven?) garbage bags of
>home made H2+air on Halloween night. They triggered them via high
>voltage and radio control from a cheap RC toy car. They used soapy
>water to avoid getting killed. One part of the story was odd: they
>said they only had to spark the end bag, then all of them exploded.
>
>Isn't UV light supposed to trigger explosions in hydrogen+chlorine mixtures?
>
>
>
>(((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))
>William J. Beaty http://staff.washington.edu/wbeaty/
>beaty, chem washington edu Research Engineer
>billb, amasci com UW Chem Dept, Bagley Hall RM74
>206-543-6195 Box 351700, Seattle, WA 98195-1700



Back