From: DAVID Katz <DAKATZ45**At_Symbol_Here**MSN.COM>
Subject: Re: [DCHAS-L] Here we go again! Another demo gone wrong
Date: Wed, 7 Nov 2018 04:36:54 +0000
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Message-ID: MWHPR11MB12481418FFE09102E8933125C5C40**At_Symbol_Here**MWHPR11MB1248.namprd11.prod.outlook.com
In-Reply-To <1ABFC53F-0E08-4C43-8579-042C90A408A8**At_Symbol_Here**dchas.org>


The demonstration is called Flaming Vapor Ramp, Flinn #AP6154.  You can access the kit on Flinn's website  https://www.flinnsci.com/flaming-vapor-ramp---chemical-demonstration-kit/ap6154/#   I could not access the directions for the demonstration.
 
I have never purchased this kit, but I have done this demonstration many times using a ramp I constructed. (That ramp was about 4 feet long, not 2 1/2 feet as supplied in the kit.) The idea is to pour hexane vapor, not liquid, down the ramp  to a lit Tea candle. It can be safely performed, but NOT as shown in the photograph on the website. Using a flask partially filled with liquid, as shown on the website, is an invitation for an accident.
 
To safely perform this demonstration using hexanes, as supplied in the kit, or any other flammable liquid with a vapor more dense than air, one should put a small amount of liquid (e.g., a few mLs - less than 5 mL) in a small flask, cover it, allow the liquid to vaporize, then pour some vapor down the ramp and quickly removing the small flask from the vicinity. One can also use a dropper to put a few drops of the flammable liquid at the top of the ramp. (This will give the same result.) All flammable liquids must be removed from the demonstration area. A safety shield is required. All safety precautions for using flammable liquids must be followed by the demonstrator.  It is essential that the demonstrator practice this demonstration in advance, with a second person present, to learn how this works.
 
Another use for the ramp is to pour some carbon dioxide down the ramp to extinguish the candle.
 
David
________________________________._________________________________________
 
  David A. Katz             
  Chemist, Educator, Expert Demonstrator, Science Communicator, and  Consultant
  Programs and workshops for teachers, schools, museums, and the public
  5003 Canby Dr.* Wilmington, DE 19808-1102 * USA
  voice: (302) 509-3282 * email: dakatz45**At_Symbol_Here**msn.com
           Visit my web site:  http://www.chymist.com
_________________________________________________________________________
----- Original Message -----
From: Kirk Hunter
To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
Sent: Friday, November 2, 2018 10:03 PM
Subject: [DCHAS-L] Here we go again! Another demo gone wrong

Hi All,

 

Here we go again. Another flammable demonstration gone wrong.

 

This was reported on ABC National News tonight (Nov 2). It happened in Georgia this week.

 

https://abcn.ws/2qofYYp

 

Fortunately, the teacher was not seriously injured (minor burns and burned hair) and none of the students were hurt.  One very, very lucky teacher!

 

I guess she was trying to show that flame will follow a vapor or that the vapor had a higher density than air.

 

 

Kirk Hunter

Waxahachie, Texas

 

 

--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org Follow us on Twitter **At_Symbol_Here**acsdchas

Previous post   |  Top of Page   |   Next post



The content of this page reflects the personal opinion(s) of the author(s) only, not the American Chemical Society, ILPI, Safety Emporium, or any other party. Use of any information on this page is at the reader's own risk. Unauthorized reproduction of these materials is prohibited. Send questions/comments about the archive to secretary@dchas.org.
The maintenance and hosting of the DCHAS-L archive is provided through the generous support of Safety Emporium.