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golfpro
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golfpro's Nitric Acid for Beginners
<strong>Silver Nitrate w/ H2SO4 and Nitrate salt</strong>
I know I had another thread like this that went sour before there was any useful info posted.
So, copper can be disolved in simply a 20% HCl solution w/ sodium nitrate. I am wondering if there is an alternative to silver nitrate for those
without nitric acid or expensive distilling equipment. Here is a video: http://www.youtube.com/watch?v=NMrWz06RtD4 I know he talks like a goon, apparently he gets the sulfate to seperate from nitric acid and filters
it out.
Can it be done to get reasonably pure silver nitrate?
Thanks
[Edited on 13-7-2013 by golfpro]
<!-- bfesser_edit_tag -->[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: given a
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[Edited on 24.8.13 by bfesser]
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chemcam
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That is just his inner nerd coming out haha. That member is now active here again, you can ask him. ScienceHideout
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cyanureeves
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i have done this method and it dissolved sterling fairly easy which i then separated the copper from silver by adding table salt and making silver
chloride.that goon speaking IS but non other than Dr.Evil
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golfpro
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What do you mean separate the silver from the copper?? Where is there copper?
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chemcam
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Copper is in sterling silver. If you have silver bullion there won't be any copper except maybe <0.001% if its 99.999% pure like most bullion.
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cyanureeves
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sterling= 92.50%silver 7.50% copper unless its brittish sterling which has uuuh ,raaather, more silver!
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golfpro
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My silver is 99.7% pure
Ok so now here is a question:
I mix ammonium nitrate (pure) in sulfuric acid (93%) drain cleaner, not the purest stuff, and this disolves quite nicely, is there any way to
precipitate ammonium sulfate here? That takes care of the sulfates and ammonium then I would be left with only concentrated nitric acid with some
impurites (how much of a problem would this be when the silver nitrate recrystalizes at room temperature?), but could still disolve silver let's say
(w/ heat) and I do the process for silver nitrate that calls for 70% nitric acid and then the evaporation.
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weiming1998
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A mixture of sulfuric acid and a nitrate salt can dissolve silver, however pure silver nitrate cannot be obtained. Due to the contamination of sulfate
ions in the mixture, silver sulfate will be produced (as it has a much lower solubility compared to the nitrate). There is no practical way of
removing the sulfate impurity (apart from distillation).
With a different (and an excess of the) nitrate salt (like barium nitrate), and if the resulting sludge is filtered, sulfate ion contamination can be
greatly reduced and this might actually produce silver nitrate, with a bit of silver lost as the sulfate. But with ammonium nitrate, it would be very
hard to produce any silver nitrate at all.
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golfpro
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How about Sodium Nitrate as the nitrate salt?? I can make that but Barium nitrate is a bit expensive for the hazmat fees.
[Edited on 17-7-2013 by golfpro]
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golfpro
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Nitric Acid concentration from distilling H2SO4/NO3
Hi, I am wondering what exactly or approximately is the concentration of nitric acid that is distilled from a mix of (93% roughly) sulfuric acid and
ammonium nitrate (pure). I only have access to a retort for distilling anything which is basically just a one peice distilling appuratus, a round bulb
flask with a narrow neck and condenser, not fancy at all.
Is this 70% acid?? There is no vacuum here. How is 100% Nitric acid attained?
I could do a titration, I would probably have to dilute the nitric x10 or something to avoid a violant reaction, problem is I do not have any
indicator, I'd have to go off of bubbles.
[Edited on 19-7-2013 by golfpro]
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subsecret
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Nitric acid approaching 100% is probably hard to come by. The azeotrope of nitric acid and water is somewhere between 60 and 70%.
| Quote: |
With good dehydrating agent, like H2SO4.
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If you chose to use sulfuric acid, be careful as this mixture would be EXTREMELY corrosive. I'm not sure how much you could increase the concentration
by distilling over H2SO4.
If possible, start with dry reagents. Don't dry ammonium nitrate with heat, as it becomes unstable and may combust or explode. As always, do research
before experimenting to prevent accidents. (I'm not sure if mixing anhydrous nitrates with H2SO4 is dangerous).
Also, do this distillation in a fume hood or outside, especially because you are using only a retort. I recommend putting the end of the retort in a
round-bottom flask or Erlenmeyer flask in an ice bath to catch all of the acid vapors. I would also recommend distilling rather slowly.
As for the titration, pH indicators containing phenolpthalein are not terribly expensive for how far they go. For a titration, you might only use 1-2
drops. If this still isn't a feasible option, you can make a pH indicator out of red cabbage. Sadly, this indicator does not change color immediately
past a certain point. The color changes are smoother, so you'd have to be very careful not to overshoot.
As always, do preliminary research to prevent accidents. Be safe.
Hope this helps.
[Edited on 19-7-2013 by Awesomeness]
Fear is what you get when caution wasn't enough.
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Pulverulescent
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| Quote: | | How is 100% Nitric acid attained? |
N2O5 is dissolved in azeotropic HNO3 to bring the conc. to 100%!
And NO2 can be reacted with water under pressure to obtain near-anhydrous acid.
But by distillation, the highest conc. is obtained from KNO3/H2SO4 mixtures!
Some NH4+ is oxidised by hot, concentrated H2SO4 during distillation, diluting the acid produced.
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
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Fantasma4500
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well 93% then you have say...
using a 100 mL 93% H2SO4 and 50g KNO3
that means you have 7g H2O
not actually sure where the water goes, but of what i know H2SO4 would be more craving for the water than the HNO3, thereby i would say approx 99%
depending on how much 'air' you let get in contact with the destillate, as the azeotropic HNO3 (in which starts at 70% by my knowledge) will be
anhydrous and hygroscopic
by my experience you really do need vacuum otherwise you might want the tube leading away to be very very low, pretty much few millimetres above the
liquid (in where HNO3 vapour cannot be)
HNO3 is a pretty heavy vapour, so if theres far up to the tube leading away chances are very high that you will only get NO2 over
vacuum otherwise fill the retort as much as possible
always wanted a retort really, be happy with it, and keep in mind that aluminium will not react with HNO3, but only slowly with NO2
if you want the HNO3 for nitrations, 70% HNO3 is pretty well all round concentration
anyhow, if you have 7g water in total, or 7 mL then by any means you would maximum in the perfect world have 7g water total in your destillate
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weiming1998
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With an excess of sulfuric acid, (almost) water-free nitric acid can be made (See http://lulelaboratory.blogspot.tw/2013/01/preparation-of-anh...). However, nitric acid made and distilled without a vacuum will always contain a
significant amount of nitrogen oxides dissolved in it. Thus, white fuming nitric acid (anhydrous nitric acid containing very small amounts of
dissolved nitrogen oxides) can only be produced by vacuum distillation.
It is important not to crank the heat up too much during distillation, as more nitric acid will decompose, producing nitrogen dioxide and water, which
dilutes down your product.
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Fantasma4500
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i think what you want to do, as this is something related to your 99% HNO3 destillation thread, you want to DILUTE your H2SO4 and then react it with
a nitrate
this is much easier than destilling high conc. HNO3 and thereafter diluting it
i would say per 100 mL 93% H2SO4 you add 23 mL/g H2O
then you SHOULD have 123 mL 70% H2SO4, althought this sounds wrong to me
anyhow; dilute the HNO3 before destillation, get the HNO3 (aluminium tubing is suitable for this destillation)
thereafter react with silver
when you react it like this you might want to be careful as NO2 is evolved and you cant avoid this
put a beaker with NH4OH aside the beaker with Ag + HNO3
if it doesnt start up gently heat the HNO3
i suppose what you want to do with the finished AgNO3 would be to precipitate a double salt, am i right?
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golfpro
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I want to precipitate a clean pure double salt. I want to collect pure AgNO3, and then use some nitric acid so I have a solution of dilute nitric acid
(don't know how dilute just yet) with disolved silver nitrate, I bubble acetylene gas through this solution to precipitate a double salt silver
acetylide. Is it correct that the silver nitrate needs to be in nitric acid in order for the double salt? Because I have no use for pure AgC2.
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golfpro
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What I gather:
-Around 85-99% nitric acid may be made by nonvacuum distilling sulfuric/ammonium nitrate mix with slight excesss sulfuric acid, this is slightly
contaminated with nitrogen dioxide and a yellowish color, (but can not be used for RDX)
My heat source for distillation will be a salty water bath heated by a flame torch, I could probably get around 110*C, or get an oil bath if need be.
I think getting 70% nitric acid by diluting the sulfuric a bit before hand would really be taking shots in the dark for the concentration.
Antiswat, what is a good procedure for the double salt AgC2*AgNO3?
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Dornier 335A
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Nitric acid is produced in the reaction. Pure Ag2C2 is only produced in a basic solution.
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PeeWee2000
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You could also get an appropriately graduated hydrometer and measure the specific gravity of the solution and compare it to this convenient chart http://www.handymath.com/cgi-bin/nitrictble2.cgi?submit=Entr... This method seems fairly straight forward and cheap to me if you dont mind waiting
a couple days after ordering one or possibly you might find one at your local hardware, as I know they are used in measuring the % Concentration of
alcohol commonly but it is probably not in the right density range to measure nitric acid. There are also other hydrometers commercially available
such as a battery acid hydrometer which might be in the right range, but youre better off getting a hydrometer specifically made for what it is youre
looking to measure.
From my personal experience when using a vacuum to synthesize it from H2SO4 and NaNO3 it came out very clear and fumed, indicating 70%+ and worked
fine for synthesizing Nitroglycerin.
What would you be using the nitric acid for anyways if you dont mind me asking golfpro?
[Edited on 20-7-2013 by PeeWee2000]
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golfpro
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I have a couple uses for nitric acid right off the top of my head, well it's cool first of all, secondly, to make silver nitrate, to make the double
salt silver acetylide, and possible RDX, I just use a nitrate salt for ETN or any Nitric ester, no sense in the expensive, tedious to make nitric acid
when nitrate salts give almost just as good yields.
BTW, I'd put any amount of ammonium nitrate in any oven, any temperature (reasonable) all day every day until the cows come home without an ounce of
worry in my mind.
Like I said, I don't have fancy vacuum equipment, only a retort.
[Edited on 20-7-2013 by golfpro]
[Edited on 20-7-2013 by golfpro]
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Oscilllator
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Quote: Originally posted by weiming1998  | With an excess of sulfuric acid, (almost) water-free nitric acid can be made (See http://lulelaboratory.blogspot.tw/2013/01/preparation-of-anh...). However, nitric acid made and distilled without a vacuum will always contain a
significant amount of nitrogen oxides dissolved in it. Thus, white fuming nitric acid (anhydrous nitric acid containing very small amounts of
dissolved nitrogen oxides) can only be produced by vacuum distillation.
It is important not to crank the heat up too much during distillation, as more nitric acid will decompose, producing nitrogen dioxide and water, which
dilutes down your product. |
I have actually observed results that contradict this. If I carry out the distillation at lower temperatures, then NO2 is very visible, but if it is
carried out at higher temperatures there is barely any NO2 contamination. I have previously made a thread on this , but I don't recall receiving a
satisfactory explanation fo this phenomena.
The distillation was done with KNO3 and clear drain cleaner labelled as 98% H2SO4. The acid obtained was yellow and formed a passivation layer with
copper, indicating it is very concentrated. I have yet to do a titration on the acid, but its on my to-do list  .
The picture that on the right is a picture that was taken early on in the reaction, before it got going. The other one is from about 10 minutes later
and as you can see there is minimal NO2 contamination.
 
[Edited on 20-7-2013 by Oscilllator]
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Pulverulescent
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| Quote: | | I have actually observed results that contradict this. If I carry out the distillation at lower temperatures, then NO2 is very visible, but if it is
carried out at higher temperatures there is barely any NO2 contamination. |
This is because NO2 is swept from the flask, on forming, by increased HNO3 vapour production!
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weiming1998
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Wikipedia states that NO2 decomposes to NO and O2 (both colourless) at 150 degrees Celsius (http://en.wikipedia.org/wiki/Nitrogen_dioxide). Maybe that is why there is appears to be no NO2 in the flask.
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Fantasma4500
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he wanted the double salt
so lets see...
if you use HCl or H2SO4 it will be impossible as the AgNO3 will precipitate in SO4 or Cl salt
you want to distill some HNO3 for this
thereafter you dont need to dry it
just lead the C2H2 through the solution, a small amount of HNO3 is added to the AgNO3 to get a good double salt, instead of having non-double salt
impurities in it
the finished double-salt bangs very very loudly, dont use too much inside
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Fantasma4500
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golfpro:
view your other thread, also on a sidenot: use a tube thats very thin, then you will get smaller C2H2 bubbles and then you will need less gas to react
it
perhaps make tiny holes in the bottom of the hose, and stopper the end so you get a stream of micro bubbles?
finished product also needs to be absolutely dry before it will do anything interesting; store away from light / UV, speeds decomposition up alot
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