GeneralChemTutor
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ammonium nitrate
I would like to know the theoretical chemistry in detail behind the following reactions help would be appreciated (any sites etc...):
-aluminum, ammonium nitrate, heat
-potassium nitrate and sugar, heat
-iodine and potassium perchlorate, alcohol (???)
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unionised
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Google is a good site.
Come to think of it, this one isn't bad, it even has a search function.
(How come there isn't an emoticon for sarcasm?)
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Geomancer
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What do you mean by "theoretical chemistry"? Combution/deflagration mechanisms tend to be hideously complex. Probably noone fully
understands what goes on in them. Free radicals are often important, I think.
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BromicAcid
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Just some basic ideas, don't quote me on them:
"-iodine and potassium perchlorate, alcohol (???)"
You add iodine to a solution or even a solid perchlorate you will get the iodine oxidized to the periodate and the perchlorate will be reduced to
chlorine. The alcohol in the mix add considerably though, you might end up with a perchlorate/iodate ester such as ethyl perchlorate which has been
covered at this site but if this is done in the solid state that will be a no-go, it will just burst into flame or deflagerate depending on the
amounts of reactants present in what combination.
"potassium nitrate and sugar, heat"
That's the old smoke bomb. The KNO3 is usually present in less then stoichiometric amounts because you want some carbon to remain uncombined to
give the smoke particulate. Of course you know this is a combustion reaction.
2KNO3 ---> K2O + N2 + 2 1/2O2
C6H12O6 ---> 6C + 6H2O
Combine the reactions however you want to destroy some of that carbon, but those are in individual decompositions that those reactants go through at
high temperature, the oxygen generated by the KNO3 at those temperatures coupled with the already decomposing sugar helps to initiate the combustion
and the remainder of the KNO3 propagates it.
"aluminum, ammonium nitrate, heat"
Inital step is the decomposition of the ammonium nitrate, however it has two routes:
NH4NO3 ---> N2O + 2H2O
Or at higher temperatures:
NH4NO3 ---> N2 + 2H2O + 1/2O2
In this reaction the second reaction will predominate due to the exothermic nature of the aluminum going to the oxide. However the nitrous oxide is
one of the only common gasses other then oxygen that supports combustion. So either way.
What it all comes down to in the first two reactions is the stability of the bonds, nitrates are inherently unstable to heat with respect to their
elements so heat is the catalyst. The oxygen plus the elevated temperatures needed to produce it initiate the combustion, oxygen comes into contact
with the surface of the burnable material and at elevated temperatures oxidizes is, when the amount of heat put off by the oxidation exceeds the rate
that it can radiate it, it propagates through the mass and combustion takes place.
The last reaction deals with iodine being easily oxidized by the perchlorate the alcohol being easily flamable/able to form the ester.
Yeah, this kind of rambled and I oversimplified quite a bit, there is some interesting reactions involving free radicals that I skimmed over and I
don't think I was detailed enough but I was just trying to get across some of the ideas.
[Edited on 3/26/2004 by BromicAcid]
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GeneralChemTutor
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Thank you for all of your help. I was at the time reading Dancing Naked in the Minefield by Kary B. Mullis and he had mentioned some of these
chemicals. I wished to know more details behind the reactions...reaction mechanisms, in light of theoretical chemistry (free energy), and any new
aspect which spans beyond general chemistry. Any new information would be appreciated, also sources , particularly internet sources.
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