From: "Kennedy, Sheila" <s1kennedy**At_Symbol_Here**UCSD.EDU>
Subject: Re: [DCHAS-L] identify demo?
Date: November 1, 2012 12:50:53 PM EDT
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Message-ID: <E47FDC2A518DB340B436567ED09B8CF58C37AB6CFA**At_Symbol_Here**>

This is the reaction used in old (pre-electric) miners' headlamps. The water and carbide are combined in a closed base of the lamp and the acetylene is vented through the burner nozzle. [I may still have a few of these tucked into the stuff in my garage - we tried using them for bicycle lamps MANY years ago & found them very finicky.]

Sheila Kennedy, C.H.O.
Safety Coordinator | Teaching Laboratories
UCSD Chemistry & Biochemistry
s1kennedy**At_Symbol_Here** |

From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Jeff Tenney
Sent: Thursday, November 01, 2012 8:17 AM
Subject: Re: [DCHAS-L] identify demo?

The reaction that takes place inside the pumpkin uses calcium carbide to generate a very small amount of acetylene gas. When the gas is ignited, a tremendous amount of energy is released, which pushes the pieces of previously carved pumpkin out. Acetylene gas is very explosive. Mixtures with air containing between 3% and 82% acetylene are explosive on ignition.

The above is from:

It is just an explosive way to try to spark students interests in chemistry.

From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Mary Beth Mulcahy
Sent: Thursday, November 01, 2012 10:00 AM
Subject: [DCHAS-L] identify demo?

Does anyone know what the demo in this experiment was suppose to be? I'm guessing ethanol environment that was suppose to be sparked and then fire shooting out of the openings in the pumpkin.

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