As a long time demonstrator, I have used the 70% isopropyl alcohol water
mixture (50% mixture) for years for the non-burning dollar trick as part of a
chemical magic show. I try to get the largest denomination possible and
have actually used a $100 bill. That said, The demonstration is
always performed over a non-flammable surface and away from the beaker of
water-alcohol mixture. The dollar is always held with a pair of tongs and
is away from my body and my clothes. Most times I perform this I am
wearing my lab coat, so my clothing is constrained.
I would only let a student perform this demonstration if I have personally
supervised that individual in the proper procedure and only with proper
supervision during the final presentation with proper safety equipment present
(e.g., a fire extinguisher).
Setting a person's hands on fire is total act of stupidity by any teacher,
no matter how safe that individual thinks the experiment may be. There are
too many safe demonstrations that illustrate principles of chemistry without
having to resort to fire, smoke, and explosions or presenting the
appearance of putting one in danger. The phrase "don't try this at home"
is an invitation for someone to try it.
Should anyone still consider performing such an experiment, make sure your
multimillion dollar liability insurance policy premium is paid.
Although I doubt that the insurance company would cover you due to your
disregard for the safety of others.
David Katz
_________________________________________________________________________
David A.
Katz
Chemist, Educator, Expert Demonstrator, Science Communicator, and
Consultant
Programs and workshops for teachers, schools,
museums, and the public
133 N. Desert Stream Dr. * Tucson, AZ
85745-2277 * USA
voice/fax: (520) 624-2207 * email:
dakatz45**At_Symbol_Here**msn.com
Visit my web site:
http://www.chymist.com_________________________________________________________________________
----- Original Message -----
Sent: Wednesday, February 01, 2012 10:49
AM
Subject: Re: [DCHAS-L] FW: ACS
Thursday
Well, personally, I've used pentane which works pretty well due to the
low boiling point (36 C). But I would never let students do anything
with fire, of course. That said, isopropanol/water works great for
the burning $20 bill trick, especially when it's one you've taken from someone
in the audience. The demo is good - but letting students play with fire
in that manner is, of course, professionally derelict.
What this teacher is talking about leads to kids doing this on their own.
Which leads to this:
or kids trying
it with something else, like gasoline....
Obviously, try to dissuade this person based on the high risk, near-zero
pedagogical content, and personal/professional liability.
And then tell her that if you ever hear of her even contemplating doing
this with students again, that you'll contact the principal, superintendent,
school board, fire marshal, and local media to make sure it stops. And
that she ever has a student injured or killed as a direct or indirect result
of this class activity that you will be first to testify for the
prosecution/plaintiff against her.
Rob Toreki
======================================================
Safety Emporium - Lab & Safety Supplies featuring brand names
Fax: (856) 553-6154, PO Box 1003, Blackwood, NJ
08012
On Feb 1, 2012, at 10:56 AM, Friedman, Donna G. wrote:
I
just received this e-mail message from a high school teacher, it is not a
joke, I am going to respond but decided to wait a bit to include your (more
thoughtful) comments.
Thanks,
Donna
Donna
G. Friedman, Ph.D.
Chair,
Department of Chemistry
St.
Louis Community College at Florissant Valley
3400
Pershall Rd.
St.
Louis, MO 63135
314-513-4388
Subject: FW: ACS
Thursday
Hello
fellow teachers!
I
have a quick question. Not sure if I can make it on Thursday, so
thought I had best send this e-mail. I normally have my students light
their hands on fire with a mixture of isopropyl and water. (I test it
first with a paper towel to make sure it doesn';t burn.) My students
have said there is a "cooler" way to light your hand on fire and that
Burroughs, Wentzville, etc. all do this cooler way. We all know
students don';t always know the "real story", but is there a cooler (more
exciting, brighter) way to light your hand on fire that is still
safe?
Thanks!
I would appreciate your help on this matter!!
Melanie
Melanie
Shedd
Principia
Upper School
