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User
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Please give some more explanation about what you are trying to say..
I combination with sulfuric acid and than distilling would not be that useful, the ammonium nitrate breaks down quite easily.
What a fine day for chemistry this is.
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12AX7
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Yes, read the rest of this thread.
Tim
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hissingnoise
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Yes you can, but the acid will be dilute as oxidation of NH4NO3 by H2SO4 produces H2O + N2.
KNO3 and NaNO3 are more suitable---NaNO3, being very hygroscopic should be dried thoroughly before addition to H2SO4. . .
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darel
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mikkello mentioned saltpeter and sodium bisulfate make NO2. what is the complete reaction?
KNO3 + NAHSO4 + Heat = NO2 + ???
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gnitseretni
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Anyone ever tried reacting nitrogen dioxide with hydrogen chloride?
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Formatik
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Quote: Originally posted by darel  | mikkello mentioned saltpeter and sodium bisulfate make NO2. what is the complete reaction?
KNO3 + NaHSO4 + Heat = NO2 + ??? |
I doubt NO2 forms as a direct result. So: 2 NaHSO4 + 2 KNO3 = 2 HNO3 + K2SO4 + Na2SO4
HNO3 then decomposes when heated.
NO2Cl forms next to Cl2 and NOCl by reaction of gaseous HCl with liquid NO2 at -22° (R. Müller, Lieb. Ann. 122 [1862] 1). The nitroxo chlorides do
yield nitric or nitrous acid with water, but how would you isolate it from HCl (which reacts again)?
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gnitseretni
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Use NO2 gas, not liquid.
See patent 4557920
React HCl gas with NO2 gas, you get NOCl gas and HNO3 in the form of precipitated liquid droplets. No isolating anything.
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Formatik
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The usefulness is limited to depending on NO2 already made. Say if you made the NO2 from a metal nitrate directly, you can just treat with H2SO4 as
usual and get the fuming nitric acid. If you get your NO2 from something like the Birkeland–Eyde process, then dry it first (silica gel) and then
you can use that additional patent setup (more work than I would like to do, though).
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hissingnoise
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Making HNO3 by distillation from KNO3/H2SO4 is by far the most practical method and the glassware needed is within everyone's reach.
There is no real need to go the NO2 route, and it never really works as well as the textbook examples, anyway. . .
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darel
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Like Centimeter, I to look for another means of producing nitric acid without he use of sulfuric acid. It is relatively expensive and you can't get
the sulfuric acid back. I looked onto using HCL because it's 7$ gal vs 28 for sulfuric. My plan is to make NO2 and oxidize it with an ozone. Iam
working on the generator. The absorbtion tower for the NO2 and water is inefficient. But N2O5 absorbs much better with water and concentrations can be
made up to 100%.
But using sulfuric acid/ nitrate salt method, would it be possible to regenerate the sulfuric acid via:
H2SO4 + KNO3 = HNO3 + KHSO4
KHSO4 + 350C = K2S2O7 + H2O
K2S2O7 + C = K2S2O5 + CO2
K2S2O5 + 200C = K2O + 2SO2
The sulfur dioxide will be percolated through hydrogen peroxide or mixed with O3 and into water to make H2SO4.
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hissingnoise
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N2O5 dissolves readily in HNO3 and the resulting mixture is a more powerful nitrating agent than HNO3 alone. . .
Some members have used thermal decomposition of pyrosulphate;
Na2S2O7---> SO3 + Na2SO4, to produce oleum but with limited success.
You could though, look for cheaper drain-cleaner but in any case, $28 gal isn't exactly prohibitive---you'll distill quite a bit of HNO3 with a
gallon.
[Edited on 13-7-2009 by hissingnoise]
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darel
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I have been using a vaccum pump with an absorbtion train and it does alright for protecting the pump from sucking in corrosive fumes. But I do get a
similar result as the pictures Mr. Pyro shared. I am looking into an aspirator. what kind of water pressure is needed to pull a 30 mm hg vaccum?
I am also looking into using the same water instead of having the hose running for an hour. Contrabasso mentioned using a bilge pump for
recirculation. I don't think these will work because the pressure behind these pumps aren't high. What about a pressure washer. Could those motors be
rigged up for such an apparatus?
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DJF90
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Hissingnoise - I believe garage chemist made fantastic progress on the production of SO3/Oleum from sodium bisulfate via the pyrosulfate, having a
very good yeild indeed (I seem to remember ~20g SO3 from 100g NaHSO4?). This can hardly be called "limited success".
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chloric1
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| Quote: Originally posted by darel | Like Centimeter, I to look for another means of producing nitric acid without he use of sulfuric acid. It is relatively expensive and you can't get
the sulfuric acid back. I looked onto using HCL because it's 7$ gal vs 28 for sulfuric. My plan is to make NO2 and oxidize it with an ozone. Iam
working on the generator. The absorbtion tower for the NO2 and water is inefficient. But N2O5 absorbs much better with water and concentrations can be
made up to 100%.
But using sulfuric acid/ nitrate salt method, would it be possible to regenerate the sulfuric acid via:
H2SO4 + KNO3 = HNO3 + KHSO4
KHSO4 + 350C = K2S2O7 + H2O
K2S2O7 + C = K2S2O5 + CO2
K2S2O5 + 200C = K2O + 2SO2
The sulfur dioxide will be percolated through hydrogen peroxide or mixed with O3 and into water to make H2SO4. |
Darel, the stochiometry looks solid but in reality your reactions will never happen. Firstly, carbon will reduce sulfate ll the way to sulfide.
Secondly, I have personally heated dry solid metabisulfite with the aim to make SO2 only to discover is that the salt goes through a redox
decomposition. The results are sodium sulfate, sodium sulfide and very llittle SO2.
Fellow molecular manipulator
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uchiacon
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Hey guys, I've just purchased about $150NZD worth of vacuum distillation labware(1L to a 500ml boiling flask) and I plan to conc the 68% nitric
azeotrope into 98% with concentrated battery acid.
Here in NZ(no, we aren't a state of australia) I can buy 25L of 68-70% nitric for $75NZD at the hydroponics shop. Can also buy 30-40% sulfuric
acid(battery electrolyte) for $80NZD for 20L at the car battery shop, or $8-10/L in smaller amounts at the motorcycle shop. So at current exchange
rates(70c US to $1 NZD) the nitric costs $44US and the sulfuric at $47 US. You guys obviously aren't looking hard enough, we're talking NZ here!
I plan to make a venturi vacuum pump with a 30PSI waterpump I bought recently. It pumps 46L/min so I might need a large container... does anybody have
any plans or tips or guides?? I have no idea on how I'm going to make a aspirator to create the vacuum, or on any of the specifics of pipe sizing in
the aspirator etc... should I buy one or make it ?
And lowering the vapour point of water increased vacuum(along with ice in the reseviour), and I heard ethylene glycol works, but that it causes froth.
Anything else that might work?
And I have the choice of a water bath or heating mantle, I'd guess that I might want something cooler(waterbath) if I make a decent vacuum, around the
area of 60 degrees to avoid decomposition.
Technically speaking, if I'm only concentrating the acid(and losing hardly anything to decomp), I should get a relatively high yield correct?
Oh, and goes anybody use vacuum grease? Supposedly you need to to keep a good vacuum, but my glassware is fairly airtight and thick. Where might I get
it anyway?
And you guys might want to check out your pottery shops for glazes and colourants, its crazy the stuff some of them stock... Vanadium
pentoxide(sulfuric synth), lithium compounds....
Cheers guys
[Edited on 04-07-09 by uchiacon]
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JohnWW
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| Quote: | | Uchiacon: Hey guys, I've just purchased about $150NZD worth of vacuum distillation labware(1L to a 500ml boiling flask) and I plan to conc the 68%
nitric azeotrope into 98% with concentrated battery acid. (cut) |
Where did you get that labware from, also the heating mantle?
| Quote: | | Uchiacon: I plan to make a venturi vacuum pump with a 30PSI waterpump I bought recently. It pumps 46L/min so I might need a large container... does
anybody have any plans or tips or guides?? I have no idea on how I'm going to make a aspirator to create the vacuum, or on any of the specifics of
pipe sizing in the aspirator etc... should I buy one or make it? |
Although 30 psi would be enough if it were properly configured (normal atmospheric pressure being 14.7 psi), ordinary water-pumps are unsuitable for
use as vacuum pumps because they have to be "primed" with water or other liquid. They would wear out in no time otherwise, and are not designed to
operate as gas compressors. You need a proper vacuum pump, to run a vacuum line from; an old British brand of them with which I am familiar is
Edwards.
| Quote: | | Uchiacon: Oh, and goes anybody use vacuum grease? Supposedly you need to to keep a good vacuum, but my glassware is fairly airtight and thick. Where
might I get it anyway? |
A brand of proper vacuum joint and stopcock grease with which I am familiar is "Apiezon L". Petroleum jelly a.k.a. Vaseline may be used to some extent
as a cheap substitute, but it is somewhat less viscous; an automotive grease, sold in tins and in grease gun cartridges, would be better as a
substitute. But a silicone grease would be preferable to a paraffin grease, from the points of view of flammability and volatility.
[Edited on 18-8-09 by JohnWW]
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uchiacon
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*facepalm*
The water pump is meant for use in a water aspiration station, i.e. instead of attaching a hydroaspirator to a tap, you attach it to a pipe leading
off from the water pump... hence venturi vacuum pump lol. Ice in the resivour also allows you to bring down water temp more than with a household
tap... and you recirculate water.
I got my labware for labwarehouse.co.nz, the guy is very reasonable. Just give him a phonecall or something and tell him Logan referred you.
I plan on making the heating mantle and magnetic stirrer with help from this thread www.sciencemadness.org/talk/viewthread.php?tid=6764#pid76986
Hey, but John, got nitric? 
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hodges
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Another Way
I was watching chemistry videos on YouTube and ran across what appears to be an interesting new idea for making nitric acid. Basically if you have
hydrochloric acid and a nitrate, you mix the two to get nitrate ions. This mixture can attack copper, producing various oxides of nitrogen as a
byproduct. You collect the oxides and bubble them through H2O2 or even water and you get nitric acid.
http://www.youtube.com/watch?v=2yE7v4wkuZU
This is an interesting and novel technique assuming it works as shown in the video.
Back when I was in high school, I wanted nitric acid but could not get it. I thought along the same lines as the author of the above video - I wanted
to generate nitrogen oxides so I could bubble them through water, but all I had was HCl. So I always tried to reduce my potassium nitrate to nitrite,
using pyro compositions. Never had much luck though. As I recall, only if I poured HCl on the nitrite while it was still very hot would I get any
brown gas, even even then just a trace. To think all I would have had to do to use copper with my HCl and KNO3....
Hodges
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Rich_Insane
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Would Ca(NO3)2 work well? This yields two NO3 ions.
If I added 100 gm of Ca(NO3)2 and just as much H2SO4, I would get double the HNO3. The only problem is the concentration, and the fact that I only
have an Ahlinn Condenser without any joints or adapters (hence the fact that I would have to build something or use some other method).
Does this sound efficient?
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DJF90
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Think again. CaSO4 will form a protective layer on the calcium nitrate. One reason why H2SO4 doesnt eat concrete very well (And HCl does a marvellous
job...). Ca(NO3)2 does thermally decompose quite easy to give NO2 that can be used as in the above video to give nitric acid of similar quality.
2Ca(NO3)2 => 2CaO + 4NO2 + O2
The NO2 should dissolve in water to give nitric acid. The O2 produced should help the process.
4NO2 + O2 +2H2O => 4HNO3
WOW! The gas mix just happens to have the right stoichiometry! Arent you in luck. Thermal decomp occurs at about 400C IIRC, well within reach. Make
sure the evolved gases have a long path through the water to ensure maximum absorbsion.
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uchiacon
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Hey guys,
I haven't seen many people bother with a magnetic stirrer for their distillations under vacuum. I was told bumping would be a problem, but is it even
needed? I mean, in a 1L boiling flask filled with 250mls of nitric and sulfuric, will bumping be a problem at like 30torr? Would it be possible to
fill it up to 1/2 way without too much bumping?
Will a magnetic stirrer speed up the distillation? I'm thinking of making a basic hotplate with a light dimmer and nicrhome wire, and if I keep that
thin (1-2cm thick) I should be able to put my mag stirrer underneath to mix up the acids. I have an aluminium plate and some refractory cement that I
could probably use, and if I get a N42 neodymium magnet on the motor I would assume that it'd be able to turn it though the hotplate. Also tested out
that aluminium and obscuring of magnetic fields thing; it does obscure the field but its almost unnoticable. I'll use a water bath to provide the heat
too.
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User
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Although a water bath would seem quite ideal I would personally prefer a heating mantle in this case.
One of the reason is to squeeze the last nitric acid out of the mixture by adding more heat at the end, this can be considered the second fraction.
Somehow the reaction seem to never be actually ended ( might sound stupid but let me explain).
I've done a synthesis a while ago with SA & KNO3 and let te reaction run for couple of hours at same temp until not much more HNO3 was distilled.
Then raised the temp to aprox. 140 degrees. even more was collected ( lower purity)
For some reason I stored the mixture that was still in the flask and put the bottle away.
After a couple of days the mixture was sweating nitric acid and heavy condensing was found on the walls.
This flask is standing now for a month or something and it keeps doing the same thing.
Even tough I used quite much extra heat there was still NA remaining.
Well to shorten a long, somewhat pointless story.
You would be well off with a little extra heat to spare.
This way one could also take the second fraction, just not to throw it away.
And also a water bath would mean a nightmare bedtime story when your flask breaks.
[Edited on 4-9-2009 by User]
What a fine day for chemistry this is.
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dann2
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Hello,
Came accross this. It may be useful reading for the Nitric acid from Ammonium Nitrate dabblers.
Hope it has not been posted before.
Dann2
Attachment: Dehydration of Ammonium Nitrate.pdf (221kB)
This file has been downloaded 609 times
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chloric1
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@dann2-Great article co-authored by Davis L. Tenney none the less
About heating calcium nitrate- this might be a good route if your calcium nitrate is not the calcium ammonium nitrate double salt. For this, you will
need a slight excess of Ca(OH)2 to turn it all to calcium nitrate. Also, calcium oxide is a component of many glasses. Could the proceedure of
heating calcium nitrate in pyrex be safely carried out? It is stated the 400°C is all that is need to start decomposition. But if we learned
anything from garage chemist and his sulfur trioxide, it would be that the decomposition would be complete at a significantly higher temperature. I
will have to check this out for myself. I actually have a tiny amount of calcium nitrate beads left.
NOTE: A local hobbyist supply house carried chemicals in the day and I remember seeing some OLd calcium nitrate that formed a solid cake in its bottle
and it was BROWN! If this nitrate breaks down that easy maybe the temperature
does not need to be high at all.
Fellow molecular manipulator
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Picric-A
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I have made (very weak!) HNO3 from decomposing Ca(NO3)2 before.
The problem with doing this on a large scale is similar to producing benzene via decarboxylation of a benzoate with NaOH.
The CaO produced formes a hard insulating mass which prevents the mix decomposing furthur.
It works well on test tube scale though. Im not sure why your solid nitrate turned brown but you do need to heat it fairly well, i used roaring bunsen
flame which proceeded to completion (on 2g scale) Nitrate was tested by dissolving in water (not completly-CaO/OH = fairly insoluble) adding some NaOH
then adding Al granules, no NH3 noted.
[Edited on 7-9-2009 by Picric-A]
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