Sciencemadness Discussion Board

Nitric Acid that is Concentrated "Enough"

Deathunter88 - 30-3-2015 at 02:26

Super simple and easy question:
I have a bottle of nitric acid that I have titrated to be 13.5molar. That comes out to be around 63% nitric acid. My question is if it will be concentrated enough more most nitrations, synthesis etc. If not then I plan to distill it and hope for the best. Do you think I could safely distill it inside my well ventilated lab with a hose on the vacuum adapter leading outside?

Thanks.

Oscilllator - 30-3-2015 at 02:30

Do please be aware the azeotrope of HNO3 is about 68%. I suggest doing some research to find ways around this limit.

Deathunter88 - 30-3-2015 at 02:57

I may not have explained myself very well, what I mean is that is it ok to use the 63% acid when "Concentrated Nitric Acid" is needed?

Bert - 30-3-2015 at 03:52

Sorry, the answer really IS that you need to do more research.

There is a TON of information on nitration parameters and how to achieve desired concentrations available here and elsewhere- You had best consider your question on a case by case basis, there is no hard and fast rule on what concentration is required. If you find description of a procedure that merely says "concentrated nitric acid" without such information as specific gravity, %, degrees Baum- look further.

Depending on temperature and in some cases quantity of dehydrating agents such as sulfuric acid or Phosphorus pentoxide, 63% nitric acid could be used to make various grades of nitrocellulose, mono or dinitrotoluenes, lower nitrated napthalenes, nitroglycerin, PETN. Won't be much good for many other products such as TNT or RDX, although it would serve to synthesize hexamine dinitrate to be used as an RDX precursor.

aga - 30-3-2015 at 10:50

It depends on the specific reaction you want to do, which is what Bert's getting at.

68% should dissolve copper nicely, but that 32% water may well interfere horribly in one of those Dark Arcane OC reactions, whose name cannot be uttered lest he appear, and explode.