Tuesday, October 2, 2007


Remember the good ol' days of Beavis and Butthead? They were, for good or bad (mostly bad), a cultural icon, albeit a short-lived one. The creators and MTV got into a lot of trouble for B&B's affinity for "fire" [I'm not sure how to type "fire" the way Bevis said it]. I remember people were up in arms because B&B were seemingly inspiring arson and the like.

Nonetheless, I couldn't help but think of them lately and their love for "fire."

Our Math and Science division is having a fall picnic this week, complete with bonfire.

I.... I, your humble crappy blog writer, have been asked to start the bonfire [OK, that's not really true, I simply usurped the privilege from my science colleagues].

I am going to ignite the fire using nothing other than chemistry!!! Now sure, lighting a match IS chemistry, but it is too traditional. I want to light the fire in a way that is dazzling.

At this moment, I am going to use my old standby reaction, thermite. I can do that with no problem. The beauty of it is that the fire would be started totally by the movement of electrons from one element to another. No covalent bonds would be broken [at least in the starting of the fire]. What a wonderful way of transferring energy to the wood and thus igniting it.

However, I'm open to suggestions.


Captain Catalysis said...

Liquid Oxygen?


I also thought "thermite" before I finished reading your post. The problem with thermite is that you still need to light it in a "normal" way.

Maybe Gummy bears in KClO3? That way, you won't need to add any initial heat.

Chemgeek said...

Usually I ignite the thermite by using KMnO4 and glycerol. This oxidation reaction is usually enough to get the thermite going.

Ψ*Ψ said...

Ever since I had a problem one day with pentane and a bad electrical connection to a rotavap water bath, I've been engaged in a debate with my boss. What's your position on this? Fire GOOD or fire BAD?

Once the fire's going, you can throw in some copper salts for pretty colors...

Chemgeek said...

I'm pretty sure pentane and a bad electrical connection could result in fire BAD!

Maybe, I'm just boring.

Liberal Arts Chemist said...

No, no, no you have got to do it Old School.

Get a chunk of white phosphorus and dissolve it in carbon disulphide. Keep the flask sealed and some small, dry pieces of kindling half in the solution. When the time comes pull out the kindling and expose to the air. The carbon disulphide evaporates and the white phosphorus glows bright yellow green and the wood catches fire. Best done in the dark.

Chemgeek said...

the white phosphorus idea is intriguing. I may not have carbon disulfide, however.

Ψ*Ψ said...

I'm on the side of fire BAD as well.

The white phosphorus/CS2 demonstration does look pretty cool.

milkshake said...

There is one lovely version of thermite reaction that I came across by accident. Burns bright white with chunks of burning aluminum flying all over. Very easy to make in your garage. It is not impact sensitive but can stain the hell of things and ignite readius of several meters so you have to be careful when lighting it on.

You must use powdered permanganate (crystals don't work - you can grind them using old coffee grinder that goes on top of a blender) and add about 10% of sulfur powder by weight to the permanganate powder (after the grinding!!). Has to be fine sulfur powder and its there in quantity sufficient only enough to make the permanganate mix to glow (in the absence of alumina). You take this permanganate+sulfur mix and put it onto a square of heavy-duty alumina foil (Reynolds), make about 1/8 inch layer, cover with another square of Al foil and so on until you get a layer cake of 5-10 alternating permanganate and aluminum layers. Then you pour a little bigger heap of permanganate ontop in the middle, wrap it around like a burrito, add extra wrap of one aluminum foil and you have your termite charge ready. You can poke a hole in it and ignite it with a cord, or a sparkler or a drop of antifreeze or glycerine. (I used to use electrical ignitor made of a tiny resistnce wire wrapped around a match head, connected by vire to a big 4.5 V battery)