Chemistry Of Negative-X

[Douchermann]

This thread is specifically for the discussion of the chemistry involving negative-X. Not the manufacturing of said mixture since there is already a thread for that. Note: This is not proven information, this is mine and lacrima's personal opinion on how the reaction goes. If you find a problem with this, discuss it in the thread but do not flame. Thats what this thread is for; discussion.

 

Lacrima97 found the source that details the decomposition of ammonium nitrate using chlorides. I will be using ammonium chloride throughout this thread as the example for the chloride containing compound.

http://www.sfc.fr/Guiochon%20VO/decompositionVO.htm

 

5NH4NO3 --NH4Cl--> 4N2 + 2HNO3 + 9H2O + Heat

This is an exothermic reaction (Enthalpy = -1092.4) so I added "Heat" onto the end. It's used later.

Water is used to set this reaction off as it is used to start

NH4NO3 + NaOH ----> NaNO3 + NH3 + H2O

which some of you know as a source of ammonia gas.

 

At elevated temperatures, 70% HNO3 can oxidise materials. The diluted HNO3 would become 70% as the water would boil off until it reached the azeotropic point. The concentrated nitric acid would oxidise the zinc metal into zinc oxide also producing a multitude of other products. I found 9 equations thus far:

 

HNO3 + 4Zn + H2O --heat--> 4ZnO + NH3

2HNO3 + 2Zn --heat--> 2ZnO + 2NO2 + H2

2HNO3 + 2Zn --heat--> 2ZnO + H2O + N2O + O2

2HNO3 + 2Zn --heat--> 2ZnO + H2O + NO2 + NO

2HNO3 + Zn --heat--> ZnO + H2O + 2NO2

2HNO3 + 3Zn --heat--> 3ZnO + H2O + 2NO

2HNO3 + 5Zn --heat--> 5ZnO + H2O + N2

2HNO3 + 4Zn --heat--> 4ZnO + H2O + N2O

2HNO3 + 4Zn --heat--> 4ZnO + H2 + 2NO

 

The heat is neccesary in all of those reactions, otherwise Zn(NO3)2 would be formed instead of the zinc being oxidised. The very top reaction is stretching it a bit, but it is indeed plausible.

 

Lacrima has compiled all of these into one big equation (to keep from having to list the 9 above). It is as follows:

15 HNO3 + 23 Zn + H2O ----heat----> 23 ZnO + 5 NO2 + 6 H2O + NH3 + H2 + 2 N2O + 3 NO + O2 + N2

 

Now of course half of these products would react with eachother.

 

Another possibility is that the heat produced from either the decomposition reaction or the oxidation of zinc with nitric acid produces enough heat to ignite the remaining ammonium nitrate/zinc metal mixture. Oxidation of zinc with ammonium nitrate procedes as follows:

NH4NO3 + Zn ----> ZnO + N2 + 2H2O.

 

Post your personal opinion on what goes on in the reaction. If you can think of more HNO3/Zn oxidation reactions, post them. If you think this whole post is whack, post why.

[Swany]

One problem in using HNO3 as an intermediate step: If you drip HNO3 (even white fuming) on Zn powder, will it burn? But, you also have heat, molten oxidisers, catalysts, and powdered fuel in the mix. Plausible. I have seen Zn chunks placed in HNO3 to much fuming, so I belive it could be possible, and RFNA and organics are used as rocket propellants.

 

You can also initiate the reaction with a drop of HCl and no chloride, proving that the chloride ion is a catalyst, presumably for the decomposition of ammonium nitrate. The decomposition of ammonium nitrate is exothermic and would provide heat to possibly melt the ammonium nitrate and then begin the oxidation reaction of Zn rather straightforwardly.

 

Though, the reaction forming ammonia definitely does happen, as is noted by the sharp smell near the mixture. One could prove this by testing the gasses' pH.

 

So, in short:

Ammonium nitrate+catalyst->Nitrous oxide, water, heat and molten AN + Zn -> Oxidized zinc, fire, and a plethora of possible products.

[_DB_]

On United Nuclear's Negative-X page they list the chemical reaction that takes place - http://www.unitednuclear.com/negx.htm

[Douchermann]

Yes I know they say that, but I can say I'm bill gates. Doesn't make it true. I'm not saying they're wrong, I'm just saying they could be wrong. The first source I gave lists the decomp with a chloride as a completely different reaction

[lacrima97]

I believe the united nuclear "said" equation, is overly simplified.