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golfpro
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Nitric Acid yeilds from Retort?
Hey for those using retort, how much concentrated nitric acid are you getting per distillation with what amount of sulfuric and KNO3? I don't have a
problem with the purity, but I use 250ml sulfuric acid and then the proper amount of KNO3 I forgot which, and then only get 50ml of Nitric acid??? Am
I losing my acid in the way of it just not condensing and fuming off instead? I don't cool the tube on the retort but the acid drops into a ice cold
beaker. I use an oil bath at least 150* C
my retort only holds 500ml, and I don't like 300ml sulfuric yeilding only 50ml Nitric... This is with the correct amount of KNO3.
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subsecret
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Try using a cold round-bottomed flask. This will provide a larger cold surface.
Fear is what you get when caution wasn't enough.
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hissingnoise
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| Quote: | | I don't cool the tube on the retort but the acid drops into a ice cold beaker. |
On distillation, the neck of the retort heats quickly until the glass reaches the vapour temperature and the vapour then largely escapes!
You could try pushing a cooled condenser onto the neck using teflon tape to minimise leaks . . .
Otherwise, just use small quantities of reactants ─ fiddly, but you'll lose less product!
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cyanureeves
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i got a 500ml retort and never used it because of that same thing but using less reactants is what i would do also.i even thought about attaching an
aluminum tube to the neck and sticking out through a hole in my tool shed wall.i would probably have to only distill in the winter though and hope
the aluminum passivates.
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golfpro
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The distillation would work much better in the winter, but is there any way to cool the neck like wrapping a baggy of crushed ice and water and taping
it around the neck?
This would cause moitsture to condense on the neck and maybe even drip water into the beaker which is supposed to get high concentrated nitric acid
and then defeat the purpose.
I bet I'd get at least twice the amount of acid distilling in 15*F weather compared to 85*F Until then I've got to find a way to cool the neck. Maybe
a cloth dipped in ice cold water and wrap that around..
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bfesser
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<strong>golfpro</strong>, I'd appreciate it if you replied to your existing threads on very similar (or identical) topics, rather than
starting new ones. I don't know how things are run in EM, but out here, your new topics are excessive.
[edit] I've merged three of your topics on nitric acid so far, and know there is at least one more. I recommend using the search function before
posting, and posting replies in appropriate threads rather than starting new ones. <img src="../scipics/_warn.png" /> <em>If you open any
more beginnings-level topics on nitric acid, I will likely lock or remove them.</em> <img src="../scipics/_warn.png" />
[2nd edit] Oh, to hell with it! I merged all five of them—I don't care if it's a little messy; this is low-level stuff.
[Edited on 25.8.13 by bfesser]
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bfesser
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Threads Merged
24-8-2013 at 15:02 |
bfesser
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Threads Merged
24-8-2013 at 15:16 |
bfesser
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Threads Merged
24-8-2013 at 15:18 |
Kiwichemicali
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Quote: Originally posted by Pulverulescent  |
The cooled vapour condenses, dissolving NO2 and lemon-coloured acid drips from the condenser!
A small quantity of NO2 escapes the condenser, depending on cooling-water temp. but the distillate contains most of the NO2
produced! |
The method I normally use to get rid of the NOx is bubbling dry air through the nitric acid while heating it to about 50 degrees C.
Would bubbling O3 do the job quicker? I'm considering building an O3-generator as a hobby project so if it is usable to
eliminate the NOx that would be a nice application for it.
Kiwi.
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woelen
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I hardly expect the O3 from a standard O3-generator to be of any influence. Of course, the O3 will oxidize the NO2 (in combination with water) to
HNO3, but usual O3-generators only have a few tenths of percent at most of O3. The rest is air (or oxygen, if you use an oxygen supply). I have never
seen pure O3-gas and I think that making this is very difficult.
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golfpro
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maximizing distillation yields from a retort
Has anyone found a way to get maximum distillation yields from a retort? I have a 500ml retort and from 200ml sulfuric acid and 160g KNO3, I get 50ml
of Nitric Acid. I am looking for a way to get 100ml Nitric acid per 200ml sulfuric acid.
Maybe the neck slightly more angled down? I know that on a cold day I'd get more HNO3, and with less material in the retort, more nitric acid can be
attained, but this only means it's more efficient to use less each time.
I was thinking of a way to cool the neck, maybe with a bag of ice?
I figure there are people on here who used a retort and have found little things for more efficient distillation.
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PeeWee2000
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Ive never used a retort but the best way I can think of to increase your yield without using an actual condenser would be to stick the end as far as
possible into another flask submerged in an ice bath so the entire flask acts like a condenser as well as trying to cool the neck as much as possible.
http://www.youtube.com/watch?v=S8rtyRnZZMU
Theres a good visual of what I'm trying to describe but definitely don't use copper and steel for making nitric acid  .
You might also try cooling the flask with dry ice, that will cause the nitric acid to freeze but it shouldnt crack your glassware as it does not
expand like water.
[Edited on 27-9-2013 by PeeWee2000]
“Everything is relative in this world, where change alone endures.”
― Leon Trotsky
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MichiganMadScientist
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Ah the retort. I own and periodically use a retort from time to time. Unfortunately, they are just not that perfect for good distillations...but not
entirely without purpose. The idea is to try and keep the heat at just the minimum you need to distill off whatever it is you are trying to isolate.
With the retort, you don't have the advantage of a chilled condenser, so try wrapping the retort in a cold wet rag (and replace the rag with fresh
cold wet rags as they heat up). Also, make sure your collection flask is sitting in an ice bath.
Ideally, you can eventually invest in a simple distillation setup. A round bottom flask, a distillation head, a liebig condensor, and a take off. You
can probably pull this off for just under a hundred dollars on Ebay. You can even use a simple automotive siphon to circulate water through the
condenser. And after you obtain this setup, it's fairly simple to upgrade to fractional or vacuum distillation by simply buying a fractionating column
or vacuum adaptor. Then you'll be distilling like the big boys!
[Edited on 27-9-2013 by MichiganMadScientist]
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Dariusrussell
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Another thing I think of (I haven't used retort either) would be to wrap a towel soaked in freezing water (Maybe with some dry ice wrapped inside) and
wrap that around the retorts condensing end.
Depending on how long the distillation takes you may have to have a couple of towels ready.
Viel Glück!
OHp, michiganmadscientist beat me to it!
[Edited on 27-9-2013 by Dariusrussell]
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Bot0nist
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Sell it to some sucker whos into "alchemy", and use the $ to buy a proper, ground glass, distillation apperatus...
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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golfpro
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NO2 removal from anhydrous nitric acid
I know it's been talked about and I've searched but this thread can just be deleted in 2 days to save space.
If I have Pure Nitric Acid aside from NO2 contamination, how can I remove this without losing the concentration? Some places I see pasing CO2 gasses
through drives the NO2 out, sometimes I read just regular air... I've heard of adding small amounts of Urea...
I sat for a few minutes with a pipette making bubbles and saw no color change, is it a much longer process than that? How would urea react w/ the
nitric acid to drive out NO2 while keeping it very pure? Or is CO2 needed?
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AndersHoveland
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NO2 is extremely soluble in anhydrous concentrated sulfuric acid, it is taken up and reacts. The reaction can be described by the equilibrium:
2 NO2 + 3 H+ <==> NO+ + NO2+ + H3O+
The nitrosyl and nitronium ions actually exist in the form of nitrosylsulfuric acid and nitronium hydrogen sulfate. Nitrosylsulfuric acid is
surprisingly stable, it can even precipitate out as a solid in only moderately concentrated solutions of sulfuric acid (with plenty of water present),
though excess water will lead to hydrolysis.
For lower concentrations - say only 90% - the solubility of NO2 drops suddenly because the species nitronium hydrogen sulfate can no longer exist in
the presence of water. (However, mixtures of nitric oxide and nitrogen dioxide are easily taken up by more moderately concentrated solutions of
sulfuric acid, because then just nitrosylsulfuric acid can form).
In anhydrous nitric acid, however, this uptake equilibrium is not so favorable because of all the nitrate ions present, but I would imagine it still
plays a significant role in the solubility.
NO+ + NO3- --> 2 NO2
If you want to rid anhydrous nitric acid of a discoloring nitrogen dioxide impurity, the best route may be to pass a flow of dried ozone in, to
oxidize the NO2. This should only be used to remove the last remnants of NO2 impurity that cannot be removed by other methods first used.
[Edited on 30-9-2013 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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Bot0nist
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I have had success by passing dry air from a fish tank bubbler through a drying tube into a graduated cylinder of nitric acid. In the morning, the
100ml of acid was very clear...
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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AndersHoveland
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One thing to consider is that anhydrous nitric acid is very deliquescent, it will pull out traces of moisture from any gas being passed through it. If
a large volume of gas is being passed in over an extended period of time, it may be important to ensure that the gas is free from moisture. This can
be achieved by passing the gas through a column of finely pulverized baked calcium chloride.
CO2 seems like a good gas to use to help pass out and displace most of the NO2, if there is a lot of NO2 in there. Another possibility may be reduced
pressure, though one suspects the acid fumes would probably be very corrosive on your vacuum pump.
[Edited on 30-9-2013 by AndersHoveland]
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chornedsnorkack
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How efficient is crystallization for HNO3 purification? The melting point of nitric acid is -42. Is slightly impure HNO3 (traces of water, NO2 et
cetera) in the -40-s a viscous substance that is poorly crystalizable, or is it easily frozen leaving excess water and NO2 in the liquid?
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golfpro
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Ok, if I bubbled CO2 gas continuously for 10 minutes through would this do it? I know there are many variables, but I'd like to know if that would be
a 10 hourish process or 10 minutes.
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golfpro
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68% concentration of a solution, by weight or volume?
If we have 1L of 68% Nitric acid, is there 680ml of pure HNO3 and the other 320ml is water? Or is 68% of the Liter By MASS composed of pure HNO3 with
the rest being water?
[Edited on 16-10-2013 by golfpro]
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gsd
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My understanding is when nothing else is specified, the concentration is in "weight by weight" (w/w) basis. So when you have 1 lit of 68 % Nitric acid
you actually have 1 * (density of 68% HNO3) * 0.68 kg of 100% HNO3 dissolved in 1 * (density of 68 % HNO3) * 0.32 kg of water.
gsd
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quantumchromodynamics
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by weight
68% nitric acid means 68% of the weight is HNO3 and 32% of the weight is H2O. The density of HNO3 is going to be different (thicker) than the density
of H2O, so the volume of HNO3 is going to be less than 680ml per liter of acid. You need the density of nitric acid to compute relative volumes.
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*FWOOSH*
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I'll back up the previous answers. A solution expressed in % is always a proportion of solute mass to total solution mass. 68% HNO3 means 0.68g HNO3
per 1.00g acid solution. The other 0.32g should be water in this case, but this won't be the case with every other solution out there (stabilizers,
buffers, etc). I generally always convert % to M as a matter of personal preference, mass ratios can be misleading.
For example:
-Large molecules (especially if you get into organics) can have very high mass % concentrations and still be quite low in molar concentration.
-1L of solution is NOT equal to 1000g of solution. This is a characteristic of water at room temperature.
-You really shouldn't measure out a mass% solution by volume unless you've done the proper calculations (densities, Molarity, etc).
My two cents , sorry if I ranted, this insistence on % strength ratings has
always been a pet peeve.
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golfpro
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NaNO3 instead of KNO3 for nitric acid distillation
Hi,
I have lost my source of KNO3 which I distilled from H2SO4 to produce HNO3, I may no longer be able to produce 99% Nitric acid unless I find
something to replace the KNO3, so would NaNO3 work as a substitute here?
there is more Nitrate concentration w/ sodium nitrate than potassium nitrate..
Kind of weird, Lowes, Home depot, and Walmart all pulled stump remover off of their shelves seemingly in the same day.
[Edited on 24-10-2013 by golfpro]
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elementcollector1
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NaNO3 will work just fine. Make sure to readjust the stoichiometry as needed. Ammonium nitrate from cold packs works as well.
(I wouldn't give up so quickly - even if all your OTC sources disappear, there are always online sources...)
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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