dynamite
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cheapest way to 96% hno3
I think the cheapest way to prepare 96% HNO3 is this NH4NO3+H2SO4=HNO3+NH4HSO4 but this wold be better 2NH4NO3+H2SO4=2HNO3+(NH4)2SO4 but does it work
and if it does how. 
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Madog
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useing ammonium nitrate is bad cause the NH3 can cause side reactions creating NO2, surely makeing it at least yellow.
the second reaction works, but it needs to be at a high temp, high enough that alot of the HNO3 decomposes yielding red HNO3
Most people outgrow their pyro tendencies, we are the ones who\'s tendencies outgrew us.
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Theoretic
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If you don't mind HNO3 being 98%, and not 96%, you could use Ca(NO3)2 with 98% H2SO4. Insoluble sulfate is left over.
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I am a fish
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| Quote: | Originally posted by Theoretic
If you don't mind HNO3 being 98%, and not 96%, you could use Ca(NO3)2 with 98% H2SO4. Insoluble sulfate is left over. |
In theory nitric acid will be produced. However in practice, the precipitate will be in the form of a thick gel from which it is extremely difficult
to extract the nitric acid.
A better way to go is to buy 35% nitric acid (as pH minus from a hydroponics supplier), and then dehydrate this with anhydrous magnesium nitrate
(which can be prepared by mixing solutions of magnesium sulphate and sodium hydroxide and then reacting the resulting precipitate of magnesium
hydroxide with nitric acid).
1f `/0u (4|\\| |234d 7|-|15, `/0u |234||`/ |\\|33d 70 937 0u7 /\\/\\0|23.
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vulture
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Quite a wasteful way of preparing magnesiumnitrate, especially because you're wasting nitric acid!
Ca(NO3)2 + MgSO4 ---> CaSO4 + Mg(NO3)2
Allows for quite a pure product, since CaSO4 is insoluble, forcing equilibrium to the right.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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rikkitikkitavi
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there are quite a few patents describing extractive distillation of HNO3 with various waterabsorbing nitrates , everything from K,Li,Mg,Ca to
Al(NO3)3, they all have the effect that they shift the azeotrope. search and you shalt find ! (because I have lost the file describing them, but it
was UK and US patents)
Theoretic, I have tried with Ca(NO3)2 and H2SO4, first there is a problem creating anhydrous Ca(NO3)2 , it is extremely hygroscopic when anhydrous,
second , exactly like I am a fish describes , an insoluble skin of CaSO4 formes, but this also dissolves in the sulfuric acid (CaSO4+H2SO4 = Ca(2+) +
2 HSO4(-), but still reaction is sloooow. , because I never got any good yields of nitric . I had to heat to above 100 C to get iumes fumes of HNO3 @
100 mbar or so.
by far, cheapest way to HNO3 is to buy
[Ca(NO3)2]5*NH4NO3*10H2O,in europe a common fertilizer, heat it to 250 C in an open oven , leaving Ca(NO3)2.
This you heat to 600 C :
Ca(NO3)2 = CaO + 2 NO + 3/2 O2 @ 600 C .
NO reformes with O2 at lower temperature and the NO2 can be absorbed in water. Since you have very high concentrations of NO2 , equipment can be
smallsized (unfortunately you need about 50-100 bar and excess O2 if you want to make > 68 % HNO3). The safety problems involved i leave to you
/rickard
[Edited on 1-7-2003 by rikkitikkitavi]
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I am a fish
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| Quote: | Originally posted by vulture
Quite a wasteful way of preparing magnesiumnitrate, especially because you're wasting nitric acid!
Ca(NO3)2 + MgSO4 ---> CaSO4 + Mg(NO3)2
Allows for quite a pure product, since CaSO4 is insoluble, forcing equilibrium to the right. |
This is a poor way of making it (though admittedly cheap if you know a good source of calcium nitrate).
Firstly the reagent solutions must be dilute, otherwise the precipitate will be extremely thick and so impossible to seperate the solute from. At
suitable concentrations, the solubility of CaSO4 (2 grams per litre) will become significant and so it will contaminate the product.
Secondly the molar quantities of the reagents must be carefully mesured to prevent an excess of one from contaminating the product. This is difficult
to do, as both reagents are hygroscopic.
1f `/0u (4|\\| |234d 7|-|15, `/0u |234||`/ |\\|33d 70 937 0u7 /\\/\\0|23.
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vulture
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Use excess Ca(NO3)2. This has no effect on the performance of the Mg(NO3)2 nor on the purity of the HNO3.
Wouldn't Ca(NO3)2 alone work?
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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Theoretic
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The original question was: can NH4NO3 work? Yes it CAN!
At high temperatures the reaction of NH3/NH4+ with NO3- can be quite fast and unpleasant. But ammonia only evolves from (NH4)2SO4 at 100C and over,
while bp of 100% HNO3 is 83C (for that you need to use concentrated H2SO4). If you are super-worried about NH3 fumes, use the amount of H2SO4 that
would form NH4HSO4 straight away.
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the_alchemist
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Cleaner?
My only question is what would have the cleaner reaction in making HNO3, ammonium nitrate or pottasium nitrate?
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