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cyanureeves
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making nitric acid
 i have
made nitric acid many times but this weekend everything went wrong.i usually just eyeball the sodium nitrate to sulfuric acid ratio when preparing for
distillation.i have been preparing nitrate from sodium hydroxide and ammonium nitrate for a week using 50g sodium hydroxide to 100g ammonium nitrate.i
am using reagent sulfuric and i have scaled up 3x as shown on nurd rage's youtube video.all i made were bubbles and bubbles for six straight hours and
the bubbles never stopped. i was pissed that all my sulfuric acid is almost gone so i am thinking of just using ammonium nitrate and rooto sulfuric
acid. there is a video on youtube that shows this being done but have heard that some nitric is wasted.will the by product left be ammonium sulfate?is
ammonium nitrate more dangerous than using sodium or potassium nitrate or is it just more wasteful?will the nitric be good?it never really mattered
what ratio acid to nitrate i used when i prepared it from prills before and it seemed this time there was too much sodium hydroxide.there was a huge
red cloud when i took down my glassware and hosed it down on the lawn.could it be that i might have urea in my ammoniun nitrate?
.
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elementcollector1
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If you watched Nurdrage's video, I do believe he said 'any nitrate salt works'.
Also, learn stoichiometry: http://theodoregray.com/PeriodicTable/MSP/BalanceReactions
As long as you have a good distilling apparatus, your nitric should be just fine.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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Oscilllator
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There is no reason you should make sodium nitrate from ammonium nitrate at all. NH4NO3 will work just as well as sodium nitrate, even better
considering sodium nitrates hygroscopy. Also you will inevitably lose some of the nitrate when changing it from NH4NO3 -> NaNO3
As for your ratios and quantities used, why did you scale it up when it wasn't working? makes no sense. And if you want to maximise your chances of
success, I suggest you weigh out your chemicals instead of eyeballing them. Use a stoichiometric ratio for best yields.
If you don't know how to figure out the correct ratio, that's ok  . There are many
websites to help you figure it out and if you want you can get some help from me/other members.
Oh yeah, and I dont think your NH4NO3 will have urea in it unless the urea was somehow mixed with the ammonium nitrate. They are made using different
processes entirely (although they both use ammonia of course).
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cyanureeves
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thank you gentlemen,thanks for the link. i will be making nitric acid out of ammonium nitrate on christmas day then and the cold packs i got the
ammonium nitrate from listed only ammonium nitrate as active ingredient.i think i'm gonna enjoy this nitrate even though i ordered potassium nitrate
off e-bay.if i have ammonium sulfate as by product i will save it to use as an ammonia generator.simply havin a wonderful christmas time(paul
mccartney).
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plante1999
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Cyanureeves, do NOT use ammonium nitrate. You will have huge lose. Ammonium nitrate dehydrate to make nitrous oxide, This really reduce your yield and
dilute a lot your acid. Use stochiometry and make sodium nitrate. By the way, how is your project going (please U2U).
[Edited on 24-12-2012 by plante1999]
I never asked for this.
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Vargouille
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Is the dehydration of ammonium nitrate significant in this case? I know that UC235 made a video making HNO3 with ammonium nitrate under vacuum, and he
reported a yield of 93%, but perhaps the vacuum prevents the dehydration. ReactionFactory also made a video using ammonium nitrate, and aside from the
fuming upon addition of ammonium nitrate to sulfuric acid that UC235 also noted, no significant loss was noted, nor were any of the characteristics of
nitrous oxide noted. Any major dilution of nitric acid would be mainly due to nitrogen dioxide, the product of the thermal decomposition of ntiric
acid, which would occur regardless of the nitrate used. Trust me, I used KNO3 and the acid still turned out yellowish.
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plante1999
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I mean N2O, sorry, Anyway, with stochiometric sodium nitrate you get 95%+ acid, with NH4NO3 you get 70% acid, there is some lose somewhere.
[Edited on 24-12-2012 by plante1999]
I never asked for this.
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elementcollector1
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I just bought a new cold pack's worth of ammonium nitrate myself. Should I really convert it with my remaining stock of NaOH?
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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plante1999
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Use sodium bicarbonate with the ammonium nitrate.
And yes, it is recommended.
I never asked for this.
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smaerd
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Well if you're going to convert it, might as well make some ammonium hydroxide solution.
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Vargouille
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I am somewhat skeptical of that claim, Plante, especially considering that loss of HNO3 can occur with a myriad of different things. Reaction too hot,
heated too fast, water wasn't cool enough, didn't heat long enough, etc. My suggestion to the OP is to attempt multiple test runs with NH4NO3,
rigorously documenting, among others: how long the reaction went; the temperature of the mantle, oil bath, what have you; specific amounts of each
reactant; whether the sulfuric acid was cooled to prevent fuming; yield; and etc., etc.
P.S.: N2O is nitrous oxide.
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cyanureeves
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well i made nitric acid from ammonium nitrate and sulfuric and it makes nitric acid alright but the ammonium nitrate to acid is much much higher.i
still have a flask full of mostly sulfuric acid because it is still in liquid form even after cooling in the snow.the ammonium nitrate distilled in
about 5min. then it hardly distilled further.after going back and forth with plante1999 via photobucket and rapid share we came up with carbonate as
the culprit. it probably happened when i let the sodium hydroxide and ammonium nitrate slurry dry for a whole day in a coffeee pot.the hydroxide is
good and so is the ammoniun nitrate but together they made a bubbling mess. you can see it at http://s1190.beta.photobucket.com/user/scarface130/media/alb... .the bubbly one is the bad one and the one with rocks floating is the same but
just before it reached distilling temp, the clear one is the successful one with just ammonium nitrate and sulfuric. ammonium nitrate works and yield
is very very low but not much because of loss but because i think i need a 1000L boiling flask to hold more nitrate.i mean the sulfuric acid just
gobbled the nitrate unlike sodium or potassium nitrate.http://s1190.beta.photobucket.com/user/scarface130/media/album1/vid1_zps95167aeb.mp4.html and
http://s1190.beta.photobucket.com/user/scarface130/media/alb...
[Edited on 12-26-2012 by cyanureeves]
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Vargouille
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I'm not sure I completely understand your post (probably because it's almost the witching hour at Vargo-HQ), but it has been noted that the solubility
of ammonium nitrate is much higher in sulfuric acid than that of the other sulfates. Although, you say that the yield was low, and then ascribed it to
not being able to use enough nitrate. Do you mean it as "percentage yield" or just "total yield"? If the former, you may be able to improve yields by
only using one mole of ammonium nitrate per mole of sulfuric acid. My reasoning for this is that because the first equivalent is more easily formed
than the second, due to bisulfate being less acidic than sulfuric acid, the product can be removed from the reaction mixture more rapidly. The dangers
to taking too long to distill the acid are loss of product and decomposition, which are, funnily enough, the same as the dangers to trying to distill
too quickly.
Can you elaborate on what exactly it is that you did with the sodium hydroxide and the ammonium nitrate that hampered your reaction?
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zenosx
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I also tried this experiment and while it has been a while since, my lab notes listed that ammonium nitrate has a much lower decomposition temperature
than other nitrates hence the only reason I got any yield whatsoever was because I performed the reaction under vacuum.
I also have notes that from research because of the low decomposition temperature and other side reactants produced from the decomposition of ammonium
nitrate with sulfuric acid can result in an explosion. I did have some yield but it was terrible compared to potassium nitrate + h2so4 > nitric
acid + ...
I apologize that I cannot verify where I obtained this information as it has been several months since I performed this experiment, however I would do
further research before I tried it again as from what I have in my notes, the only reason I had any yield was because it was performed under vacuum.
If anyone knows why this is please clarify.
I also apologize for the horrible grammar because I am trying to dictate this to my iPhone after midnight on Christmas with a bit too much eggnog. I
remembered this experiment in the past from the large "danger do not perform again" in my lab notes that I just rechecked.
And no I do not go near my lab on eggnog Unless it is to check my lab notes for
a forum post. You would all have loved this post if I had not edited what Siri had posted for me
[Edited on 26-12-2012 by zenosx]
A question that sometimes drives me hazy: am I or are the others crazy?
Albert Einstein
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Vargouille
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The reason for that, Zenosx, is because the application of vacuum allows the nitric acid to distill at a much lower temperature than at ambient
pressure. This retards the decomposition of both it and of the ammonium nitrate. A comment on preforming this experiment with ammonium nitrate, Mr.
Home Scientist has preformed this with ammonium nitrate as well, and obtained a fairly good yield (from rough visual estimation, mind you). A significant point is
that his hot plate, by his own words, does not operate at high temperatures. This lower temperature may have been instrumental in his higher yield. A
useful variable to monitor would thus be the temperature of the oil bath used. I would suggest not allowing it to exceed 120C, but a reaction
temperature of 100C would probably be best. Hot enough to boil the nitric acid, but just low enough to prevent significant decomposition of ammonium
nitrate.
I am not certain, however, of when decomposition of the NH4NO3/H2SO4 mixture will begin, as my source of information on the subject does not study the effects of such ratios of sulfuric acid to ammonium nitrate as would be present in such
a case. If the trends posited in the work hold true at these ratios (ie if the decomposition temperature is lower when there is more sulfuric acid
than ammonium nitrate) then increasing the amount of ammonium nitrate used will be beneficial to yield, contrary to my previous advice; "if" being the
operative word.
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zenosx
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Yes I am aware that lower temps lower the boiling point of liquids, and is the point of distilling under vaccum if my post implied otherwise it was
unintentional. I was not aware that it also lowered the decomp temp as well though, thanks for that info.
If I have time today I will try to find what source gave me the impression that (NH4)(NO3) could develop explosive decomp products with sulfuric acid.
A question that sometimes drives me hazy: am I or are the others crazy?
Albert Einstein
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Vargouille
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Ah, no, that's not what I mean. The decomposition of ammonium nirate and sulfuric acid is largely unrelated to the pressure. What changes the
temperature of decomposition is the relative amount of sulfuric acid to ammonium nitrate. Because the boiling point of the liquid is decreased, the
reaction can be done at a temperature far below the decomposition temperature of the mixture. Thus, little if any ammonium nitrate decomposes.
As for explosive decomposition products, one source is the second link I gave in the preceding post. Ammonium nitrate will decompose exothermically to
form the gaseous nitrous oxide, and thence explosion.
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cyanureeves
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Vargouille what i did with amonium nitrate and hydroxide was mix both using the ratios as seen on nurd rage's video except i scaled up three x. what
you say about sulfuric acid to ammonium nitrate ratio is true in my case also and the boiling flask content is still in liquid form after all the
nitric was distilled out.the flask still looks like it does as in the video so i'm gonna reuse it and just add more ammonium nitrate to it. the one
thing i did different from nurd rage is not premix salts separately i just combined both and added water and saved the gas to my 10% store bought
ammonium hydroxide.i did notice that the ammonium nitrate dissolved super quick and so i think that if i scale up 3x then my ammonium nitrate to
hydroxide ratio has got to go up a bit.rocks can be seen in one of the videos and those same rocks are the bubble generators and i think its excess
sodium hydroxide.i crushed the sodium nitrate/hydroxide mix to a fine dust but as soon as i added sulfuric it would rock up and bubble.oh! i also
never got the sodium hydroxide/ammonium nitrate mix to crystalize,it would only leave white mush so i just let it all dry up.the ammonium nitrate
distillation gave me little yield unlike potassium or sodium nitrate so i think i will need a 1000ml flask to get a good yield.(http://s1190.beta.photobucket.com/user/scarface130/media/alb...) i dont know why this link doesnt light up in pretty blue like the other two.it's
jinxed i tell you! oooh! there it is.
[Edited on 12-26-2012 by cyanureeves]
[Edited on 12-26-2012 by cyanureeves]
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cyanureeves
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gentlemen would you believe a stupid but true story?today i made nitric again and again it failed after six runs until just this one last time i used
a stainless steel rod for stirring.i had been using a window blind wand for stirring and it was making all the bubbles. sorry for wasting your time,my
time and about a pound of nitrate and a quart of sulfuric. i will delete the videos and again i am sorry! i was starting to think aliens, the mayas,my
neighbors i dont know. on the bright side i tested all my glassware and all work fine a nitric is distilling happily as we speak.
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plante1999
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Glad you found what was the problem!
I would still test my carbonate if I were you. You might find more carbonate than you think.
I never asked for this.
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Vargouille
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Okay...?
I don't really understand why using a window blind wand (of clear plastic, I presume) would cause a failure in the reaction, but if it works it works.
As for the sodium nitrate preparation, did you add an amount of ammonium nitrate in excess to the stoichiometic amount required to react with the
sodium hydroxide? If so, that might explain your slurry problem.
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AndersHoveland
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There is some dehydration, and using ammonium nitrate can reduce the yields, but it is often not a significant problem. It begins to become more of a
problem when the nitric acid is more concentrated (above 70%), especially when being heated/distilled. Under these conditions, it may be best to
perform the distillation under reduced pressure, and minimise reaction time.
"Ammonium nitrate heated with two equivalents of sulfuric acid behaves in the normal matter and yields nitric acid" (rather than dehydration of the
ammonium nitrate)
Pelouze, Ann. chim. phys., [3] II, 47 (1841)
When ammonium nitrate is heated with a large excess of concentrated sulfuric acid, about 85% of its nitrogen is given off as nitrous oxide, the rest
in its elemental state. The dehydration does not become rapid until 150°C.
Heat/boiling can cause nitric acid over 70% concentration to partially decompose into NO2 and O2, and this can be seen as the nitric acid develops a
strong yellow to red-brown color. (this decomposition is not reversible at such high concentrations, and is why nitric acid over 70% is always
prepared under vacuum distillation)
The NO2 may potentially be able to slowly oxidize the ammonium nitrate if the distillation is too long. (for oxidation of ammonium ions by a
combination of oxides of nitrogen, see A.W. Knight. Undergraduate Thesis at California Institute of Technology (1992). "Perchloric Acid from
Ammonium Perchlorate and Oxides of Nitrogen)
Under extremely concentrated HNO3/H2SO4 (particularly superconcentrated acid) there is a tendancy for some of the ammonium to be nitrated/attacked,
but the rate of this attack is very slow (the nitronium cations in equilibrium cannot directly attack the ammonium ions, explaining the slow reaction
rate). One can conjecture what the final decomposition products through this reaction pathway would be, since the dehydration of nitramine, NH2NO2, by
concentrated sulfuric acid results in nitrosylsulfuric acid and elemental nitrogen.
Just thought I would mention it here: In a related reaction, anhydrous ammonia can be nitrated with dinitrogen pentoxide to form ammonium dinitramide.
J. C. Bottaro, P. E. Penwell and R. J. Schmitt, J. Am. Chem. Soc., 1997, 119, 9405
Ammonium nitrate does have an advantage in cold nitrations because of its high solubility.
[Edited on 5-1-2013 by AndersHoveland]
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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cyanureeves
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i have not made any more ammonium nitrate/sodium hydroxide mix to correct anything at all because i used it all. i got the slurry in a vinegar jar and
is sitting there red fuming angry but the clear plastic wand did instantly turn opaque foggy when it contacted the slurry mix. i will just stick to
the same ratios nurd rage used in his video because it has worked before for me. i will throw all the slurry away and count my loss but hard to
swallow it was the plastic that caused the bubbling. i mean how long does it take to stir nitrate and sulfuric acid? 2-3 seconds? and still freaking
bubbles galore!however you know i collected about 40ml all together of all the nitric that came over at low temperature before it would foam. the very
yellow nitric is not very strong but it did entirely dissolve a penny but i had to use more than the usual,anyway its a keeper.
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AndersHoveland
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You do realise that American 1 cent coins are made from zinc? They are just plated with copper. (the ones before 1982 are 95% copper, however)
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K12Chemistry
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it dissolved the whole penny because nitric acid dissolves copper and zinc
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