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Re: Mini-volcano

Is it important to use the dichromate? (not recommended anymore).

I would think a length of hobby wick (aka fuse cord) would produce all the
smoke, flame, and sparks you would need - w/o haz mat waste.

Also look into a demo using a small pile of potassium permanganate and a
_drop_ of glycerin on top. Produces many similar effects without the mess.
I do it on the bottom of an empty soda can - perfect shape and disposable.
<http://www.google.com/search?q=potassium+permanganate+and+glycerin+demo&btn
G=Google+Search>

Scott




--
*****************************
Scott Goelzer
Physics Teacher
Coe - Brown Northwood Academy
Northwood NH 03261
603-942-5531 ext43
sgoelzer@coebrownacademy.com
*****************************

on 11/12/01 10:47 AM, Greenberg, Jon at Jon.Greenberg@PHSCHOOL.COM wrote:

Brian, this sounds pretty good. Can you provide or refer us to a protocol
for this one?

Jon

----------
From: Brian Whatcott
Reply To: phys-l@lists.nau.edu: Forum for Physics Educators
Sent: Sunday, November 11, 2001 3:50 PM
To: PHYS-L@lists.nau.edu
Subject: Re: Mini-volcano

At 02:41 PM 11/11/01 -0500, you wrote:
Yes it is a neat demo.
Ammonium dichromate decomposes to produce chromium(III) oxide, nitrogen
gas
and water vapor. When this demo is presented in the open on a ceramic
plate
or on a heat resistant padded steel gauze, the green oxide fluffy flakes
will
tend to fly around and cause a mess.x\

/snip/

Greg Darakjian


I will admit to a certain bias. I think ammonium dichromate is better
employed to
provide a photo polymer of gelatin, which when applied to a cloth and
exposed to a
u.v light shining through a high contrast photo or stencil in contact with
the cloth,
provides a delightful means of stippling paint onto a substrate when the
unlinked
gelatin is washed off, and the mask dried on a frame.

You may recognize this as a description of 'silk screen printing' .


Brian Whatcott
Altus OK Eureka!