bonemachine
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Nitric from kno3/HCL
Can someone tell me what concentration of HNO3 can i take from dissolving kno3 to 35% HCL.
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Nick F
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35% HCl is 350g per kg, = 9.59 mol/kg. D = 1.175 g/cm3, so 35% is 11.27 mol/dm3 HCl. Adding 1138g (11.27 mol) of KNO3 to 1L would therefore make a
solution containing 11.27 mol of NO3-, 11.27 mol of H+, 11.27 mol of K+, and 11.27 mol of Cl-, equivalent to 11.27 mol of HNO3 and 11.27 mol of KCl in
2.313 kg of liquid, assuming all the KNO3 dissolves. This solution would therefore be 30.7% HNO3. And you can't distil out HNO3 easily because HCl is
more volatile.
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rikkitikkitavi
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The mix would be eqvivalent to aqua regia...
KNO3 has lower solubility than KCL at room temperature- but perhaps the same could be accomplished with NaNO3 instead , which is far more soluble at
room temperature. NaCl has a almost temperature independet solubility, most likely partially preciptating.
But it would be very difficult to separate the two acids from each other.
/rickard
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Marvin
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A few thoughts,
With regard to solubilities, I dont think the information for pure water will be valid becuase of common ion and strong acids, neither will form a
bi-salt so its possible this could be made to work.
With sodium sulphate it should be possible to precipitate sodium hydrogen sulphate (or sodium chloride - either way you can make the bisulphate) which
will form nitric acid with a nitrate salt (ideally sodium nitrate in this example) at higher temperatures than are normally used for sulphuric acid.
The residue will also be more of a pain to remove, but this will be mainly sodium sulphate and can thus be recycled without furthur purification so
long as the mix starts nitrate low. Potassium sulphate could also be used.
HCl is very volatile, its a gas, but it forms a constant boiling azeotrope with water at around 20% HCl by mass (IIRC). It might be possible to make
a mixture with more or less than 20% HCl, that can be fractionally distilled into az nitric, and az hydrochloric. I dont remeber the boiling point of
each, so I'm not sure if the difference can be exploited easily. Formation of a tertiary az might happen though, if it doesnt distillation should be
exploitable whichever is the lower boiling, it just takes more work, and a more complicated setup if this is hydrochloric.
Small amounts of chloride in conc nitric can be removed by distilling from silver nitrate, but as you would need dilute nitric acid to regenerate the
silver nitrate, so I dont see this as workable preperativily.
All of these require distilling, so I think they are not likley to be of any real use. Since any process that involves adding the acid to a nitrate
directly will be fairly strong aqua regia as rickard has mentioned, some exotic nasty products like nitrosyl chloride are to be expected, and will
definatly complicate matters.
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bonemachine
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Well it is realy hard to distill nitric made out of HCL. So is there any other nitrations exept hexamine that i could do with that mix?
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Nick F
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There are no real nitrations that you can do with it, but you can form nitrate salts of organic amines with it, providing that the nitrate of the
amine is less soluble than the hydrochloride.
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Anarchist
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I have actually done this, and you will need to be careful because if you heat this at all it will give off chlorine gas, however you do need to heat
it(the heat from the average bunsen burner willl do it) and the solution will also start to bubble a lot so don't fill it too high. I still haven't
found a good way of seperating the stuff though.
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