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Specialty Chemistry Forums => Other Sciences Question Forum => Topic started by: bobdafro05 on April 17, 2004, 11:45:12 PM

Title: spontaneous combustion of white phosphorus
Post by: bobdafro05 on April 17, 2004, 11:45:12 PM
im an 11th grader working on a chemistry project. i have to demonstrate to the class what happens when a solution of white phosphorus in carbon disulfide is placed on a filter paper. the filter paper is placed on top of a graduated cylinder. i have been searching the web for explanations of why there is a ring of fire that goes down the cylinder, why it makes a barking sound, and why it burns. i already know that white phosphorus reacts with air at room temp. i kno that the carbon disulfide evaporates to allow the phosphorus and oxygen to react. is there anything else that i need to know. my teacher is very demanding and i would appreciate any knowledge given to me. or if there are any useful sites i can visit. thank you very much for your time.
Title: Re:spontaneous combustion of white phosphorus
Post by: hmx9123 on April 18, 2004, 12:00:50 AM
I can't believe your teacher allows this in his/her classroom.  This was a somewhat standard demo in the 40s and 50s, but white phosphorous is so dangerous, no one will touch it anymore.  Have you seen this done?  Does your teacher set it up for you?  And, for god's sake, why are you looking this up on the internet!?!?  That is the last place you should look.  If you get white phosphorous on your skin, you have to cut it off with a knife.  You're screwed.  You'll get horribly scarred and burned.  The other great thing about it is that it's toxic.  It takes very little to be lethal.  You'll have to excuse me if I'm skeptical that your teacher wants you to do this or knows what it could do.

If you already know that the CS2 evaporates to allow the P4 react with the air, what don't you understand about the fire and barking?  Look this up in some old chemistry texts.  Try and find some old lab manuals or demonstration books in your school or your library.  The older demo books had things like this in them.
Title: Re:spontaneous combustion of white phosphorus
Post by: hmx9123 on April 18, 2004, 12:02:54 AM
BTW, I deleted your duplicate post in the HS forum.
Title: Re:spontaneous combustion of white phosphorus
Post by: gregpawin on April 19, 2004, 12:39:39 AM
So exactly what happens when white phosphorus touches your skin?  I've seen a picture of phossy jaw, which is pretty nasty; but I do recall seeing drawings of people painting white phosphorus on each other's faces for the glowing effect.
Title: Re:spontaneous combustion of white phosphorus
Post by: hmx9123 on April 19, 2004, 02:20:28 AM
http://www.vnh.org/EWSurg/ch03/03ChemicalBurns.html

http://www.atsdr.cdc.gov/tfacts103.pdf

http://news.bbc.co.uk/hi/english/static/in_depth/world/2001/war_on_terror/special_forces/equipment/equipment_9.stm

etc.
Title: Re:spontaneous combustion of white phosphorus
Post by: Mitch on April 19, 2004, 02:56:07 AM
Boyle used to use a phosphorous paste when he use to write on himself and other people. I guess it wasn't that concentrated.
Title: Re:spontaneous combustion of white phosphorus
Post by: jdurg on April 19, 2004, 01:20:31 PM
Boyle used to use a phosphorous paste when he use to write on himself and other people. I guess it wasn't that concentrated.

Then again, we used to play with Mercury in elementary school, and they used to use mouth suction for pipettes.  It's just a matter of knowing the dangers involved with the substances, and back then they did not know.