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I am doing a science experiment with Thermite for a term project in my AP chemistry class. For safety's sake I would like to know about how much thermite releases how much energy, more specifically, what size flame, or explosion. I also don't know what type of reaction it is, a slow burning jet of fire, or a violent explosion. There was a picture in our science book that showed the reaction but there is no way to determine how much was used. Any additional information about preparation, safety, etc., will be very much appreciated. Thermite is
Fe2O3 (s) + Al(s) -> Al2O3(s) + Fe(l)
Question Date: 2003-02-20
Answer 1:

Here is a first-person account from a Post-Doctoral Chemist at UCSB: I've done a thermite reaction on a 1 kg scale using aluminum powder and magnetite (mixed iron oxide Fe3O4). I used magnetite because it's quite cheap and comes finely divided, though red oxide should be fine or better if less fine. The reaction is faster if the powders are finer, so I recommend not using fine reactants in a school setting and the scale should be less than 100g.

The reaction should be done outdoors and on a disposable, fireproof surface (I used a paving slab) in a disposable container which will be obliterated during the reaction (I used a family sized soup can).

For ignition the surface must be fresh (otherwise absorbed dampness from the air puts out the fuse) and ignited using a magnesium ribbon fuse extending down into the mixture. This fuse itself needs a fairly good gas flame to light (a bunsen, a blowtorch or one of those blue flame cigarette lighters should do the trick).

When reacting, the effect is somewhat like a Roman Candle firework (lots of vertical sparks leaping about 2 feet into the air). I have never had a problem with explosions, but the reactants should be thoroughly mixed to give smooth burning. I have never got a good metal sample out of the reaction, just some semi-metallic slag. I recommend a small scale test reaction (i.e. 1g of material) to get a feel for it before attempting anything too spectacular . For extra safety, a bucket of dry sand for covering burning metals and a bucket of water for first treatment of any accidental burns.

Spectators should be at least 6 feet away from a small reaction and a anchored piece of perspex as an explosion shield between the pot and the spectators might be a good idea. I have never gone to such lengths as this to protect my audience, but they were all consenting adults in a very informal setting.

THIS IS NOT TO BE TRIED BY SCHOOL STUDENTS.


Answer 2:

I would suggest looking at this website. It provides a very good description of the experiment. Have fun and be careful.

thermite



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