Preparation of Nitric Acid

90% nitric acid containing barely any nitrogen oxides is prepared in high yield by distilling a mixture of ammonium nitrate and drain cleaner grade sulfuric acid under vacuum. Nitric acid density information is available at this link: http://www.handymath.com/cgi-bin/nitrictble2.cgi?submit=Entry Special thanks to Ozonenerd of Reactionfactory for pointers on this preparation. The intro music clip is from "Stealing Fat" by The Dust Brothers. I believe this falls under fair use.

Category:

Science & Technology

Tags:

• nitric
• acid
• vacuum
• distillation
• reduced
• pressure
• distill
• ammonium
• nitrate
• sulfuric
• nitration
• nitrating

[OAbrey]

Long have I wanted to do aqua-regia. Nitric acid in appropriate concentration has been a bit of a sticky spot. Is there any other nitric salt besides ammonium nitrate that would work similarly?

[UC235]

@OAbrey Ammonium nitrate is by far the most suitable due to it's high solubility in sulfuric acid and if distilled at atmospheric pressure, the ammonium bisulfate will be molten when you're done, preventing an unstirrable crystalline mass like I got. I'd suspect sodium nitrate to be the next best due to it's higher solubility than potassium nitrate. You may want to dissolve in water beforehand, and have enough around to distill of the 69% azeotrope.



[99Chemicals]

Is it possible to use a grahm condenser horizontaly? I have a 200mm grahm condenser and dont have the proper glass to use it vericaly and would like to use it. My theorey is that the vapors from the boiling liquid would push the distilate through. Does anybody definatively know wether I can use the grahm condenser horizontaly?

[UC235]

@99Chemicals I can't say I've ever tried. I'd test it with something like water before you do anything hazardous in case it goes badly. You should really invest in a liebig.

[99Chemicals]

@UC235 I bought a distilation kit on Ebay and it had both West and Grahm condensers. I have used the West very sucsessfuly 3 times on simple distilation. I haven't used the Grahm yet. Isn't a Grahm a good reflux condenser?

[UC235]

@99Chemicals Not really. The tubing is narrow so liquid might have a difficult time draining back into the flask, especially with fresh vapor pushing up into the coil. Unless you are furiously boiling a solvent with a low b.p. (ether, DCM, etc.) a liebig/west condenser upright is fine for reflux. A downward grahm condenser is a very efficient condenser for the same low boilers when distilling them.

[OAbrey]

Thank you gentlemen, I have 40kg of KHNO3 I am trying to do something with. Was hoping I could substitute it without loosing too much strength...

[caliusoptimus]

after the distillation is done and cooled down, i recommend disassembling the apparatus with a 5gal bucket of water near by. as soon as you take it apart, you should set your glass into the bucket to keep fuming to a minimum, and also to minimize the amount of droplets that may hit the floor. much better than leaving trails of brown gas and nitric drippings on the way to the sink!

[ISheLLShockI]

What size Polyethylene tubing fit onto the vacuum adapter? I am buying my kit, but I am unsure what size tubing I should get, I know that tubing is more bend/flex resistant than others. I just want to get the right size.

[crapbag1997]

where did you get your ammonium nitrate

[thegodofchemistry]

@99Chemicals of course you can use it