Sciencemadness Discussion Board

Making 68% Nitric Acid

highpower48 - 10-2-2016 at 11:07

Does anyone have a good recipe for making 68% Nitric Acid. I have a 500ml distalation setup and want to use potassium nitrate as my nitrate source and of course 98% sulfuric acid. Watching the various youtube videos they either use a diff. Nitrate source or do fuming nitric acid. I'm a relative no on and not yet able to do the math needed to come up with my own stoichiometry recipe. Thanks for any help you can give me.

IrC - 10-2-2016 at 11:48

Before you made this post had you read the long thread on the subject in Technochemistry?

highpower48 - 10-2-2016 at 12:07

No I did a search and didn't come up with anything. I will try again. Thanks

highpower48 - 10-2-2016 at 12:24

Did search tecnochemistry and really didn't find what I needed. I'm going to use distillation, nothing I could find useing this. If I'm missing something could you please give me the link. Thanks

hissingnoise - 10-2-2016 at 12:28

Distill from the nitrate and add the water needed to get it down to ~70% . . .

If you want it walter-white, bubble dry, warm oxygen in until the NO2 oxidises!

IrC - 10-2-2016 at 15:32

Quote: Originally posted by highpower48  
Did search tecnochemistry and really didn't find what I needed. I'm going to use distillation, nothing I could find useing this. If I'm missing something could you please give me the link. Thanks


http://www.sciencemadness.org/talk/viewthread.php?tid=1518

Doubt you could have gone through all 12 pages this quickly so assume your searching looking at titles. In this and other threads over the years many side discussions exist which contain much useful information (including the subject in your first post here), but it does take time to go through and analyze it all. This includes snippets in various threads which are good to know as in a post in this thread:

http://www.sciencemadness.org/talk/viewthread.php?tid=63645&...

How to do a thing is good to learn but so is looking at experiences others have had where problems (dangers) to be cognizant of is also good to know.

http://www.sciencemadness.org/talk/viewthread.php?tid=13090

This thread in Prepublication, 'Preparation of Nitric Acid' by Magpie is a very good read.

http://www.sciencemadness.org/talk/viewthread.php?tid=63145

http://www.sciencemadness.org/talk/viewthread.php?tid=2176

The above thread is 19 pages on the subject. Before you do any chemistry which has inherent dangers I would take the time to read through all of these threads since the experience of many members here is a very good thing to study. You may find a better route than your initial idea as well as knowing what has gone wrong (or right) for others.

http://www.sciencemadness.org/talk/viewthread.php?tid=12899

http://www.sciencemadness.org/talk/viewthread.php?tid=25209

http://www.sciencemadness.org/talk/viewthread.php?tid=26106

http://www.sciencemadness.org/talk/viewthread.php?tid=23648

The above thread discusses one of the questions you asked.

http://www.sciencemadness.org/talk/viewthread.php?tid=20968

http://www.sciencemadness.org/talk/viewthread.php?tid=13749

http://www.sciencemadness.org/talk/viewthread.php?tid=13260

http://www.sciencemadness.org/talk/viewthread.php?tid=11345

http://www.sciencemadness.org/talk/viewthread.php?tid=8025

http://www.sciencemadness.org/talk/viewthread.php?tid=9120

http://www.sciencemadness.org/talk/viewthread.php?tid=9499

http://www.sciencemadness.org/talk/viewthread.php?tid=1851

http://www.sciencemadness.org/talk/viewthread.php?tid=401

http://www.sciencemadness.org/talk/viewthread.php?tid=5165

http://www.sciencemadness.org/talk/viewthread.php?tid=6142

http://www.sciencemadness.org/talk/viewthread.php?tid=1013

This subject has been discussed in so many threads for over 10 years on SCM I just cannot buy your statement you could not find anything when searching this site.

hyfalcon - 10-2-2016 at 16:09

Go to google and type: "site:sciencemadness.org distilling nitric acid" then read to your hearts content. Much better way to search the site rather then with the websites own search engine.

XeonTheMGPony - 10-2-2016 at 16:38

I can't help but to think you are no where ready to be playing with this stuff if you can not manage to figure out how to do a simple dilution! (Adding cold water to acid to dilute to desired value)

I would urge you to spend way more time reading, and starting with some thing far less nasty then HNO3.

Fallow the advice above, and keep finding every thing to do with the topic, the more you learn now the less you'll burn your self to a crisp later!

JJay - 10-2-2016 at 16:47

You will probably have to do a titration before the dilution. You really should be able to do the math if you're playing with that stuff.

I've also been contemplating making some nitric acid, but of course I did some distillations of more innocuous substances and titrated some milder substances like vinegar and muriatic acid, as well as playing with sulfuric acid.

highpower48 - 10-2-2016 at 16:59

Doing a dilution calculation is not the problem nor what I want. I want my distalation to work out to a 68% concentration. From what I see the 1st distalation will give about a 50% concentration and a second distalation with a temp of 121c will give me common 68%. I was avoiding producing Red Fuming Nitric Acid and then diluting that. Just needed the amounts of potassium Nitrate, water and sulfuric acid needed to do the 1ST distalation in a 500ml flask. But I do thank you for you advise.

XeonTheMGPony - 10-2-2016 at 17:13

the most efficient method is to just produce your pure nitric acid, then dilute from there. the rest of the issues is solved via precise temp controls.

Cleaner and drier your starting sulfuric and nitrate are the better the product. water at this stage is poisen to the system.

Once you have the pure clean dry product you then figure out the concentration then go from there, trying to cram every thing in your starting materials leaves for less then desired results.

If you are getting allot of NOx then you need to adjust your method, usually using a slow temp ramp up will take care of that.

Detonationology - 10-2-2016 at 17:16

Quote: Originally posted by highpower48  
Doing a dilution calculation is not the problem nor what I want. I want my distalation to work out to a 68% concentration. From what I see the 1st distalation will give about a 50% concentration and a second distalation with a temp of 121c will give me common 68%. I was avoiding producing Red Fuming Nitric Acid and then diluting that. Just needed the amounts of potassium Nitrate, water and sulfuric acid needed to do the 1ST distalation in a 500ml flask. But I do thank you for you advise.

Here is what you need to watch. This is Doug. He has many great videos and frequents this site by the name Praxichys. It sounds like this is exactly what you are looking for:

https://www.youtube.com/watch?v=mG4OaPTWPOA

[Edited on 2-11-2016 by Detonationology]

highpower48 - 10-2-2016 at 17:41

Thank you for the video link! I have watched many of his YouTube video's. Doug, Red Nile and Nurd Rage have what I consider the best videos on chemistry on YouTube... I really like the way Doug's Lab explains the whole process...

highpower48 - 10-2-2016 at 17:43

Want to thank everyone for there help to this noob. I appreciate it a lot.

Detonationology - 10-2-2016 at 17:45

Quote: Originally posted by highpower48  
I really like the way Doug's Lab explains the whole process...

I hope it helped to give you a better understanding. IMO, his method is a much easier, safer way of making 68% HNO3 than by first making fuming nitric, then diluting. Why would anyone want to deal with those godforsaken nitrogen oxides rather than conveniently distill the azeotrope at 68%? It doesn't make a bit of sense unless fuming is what you desire.

BromicAcid - 10-2-2016 at 19:37

Nice collection of threads IrC, hopefully the next time someone searches how to make nitric acid they will stumble across your compendium.

IrC - 10-2-2016 at 20:15

Quote: Originally posted by BromicAcid  
Nice collection of threads IrC, hopefully the next time someone searches how to make nitric acid they will stumble across your compendium.


Thank you. I listed every thread on the subject going back to 2003 which contained information the OP would find of great use if the time is taken to study it all. Included one thread not HNO3 specific 'Maximum boiling azeotrope', I figured the OP would find it of use working towards the 68% goal. Also searched your personal site but got hypnotized by that incredible ginormous glassware you are holding. Can I have it? I need a fishbowl for Nemo's monster Octopus.

Nitric Acid Synthesis

Richard3050 - 31-5-2016 at 16:18

I recently conducted an experiment to try and synthesize some homemade nitric acid but ran into an interesting problem. I used a procedure from NerdRage (youtube) where I reacted potassium nitrate, copper metal, and hydrochloric acid in a vacuum flask to generate NO2 gas. This was then run into a graduated cylinder containing approximately 15% hydrogen peroxide. After approximately 20 minutes of letting this apparatus run a descent quantity of NO2 was clearly being produced (based off of the orange - brown color of the gas), and was bubbling well through the peroxide. After the bubbling stopped (at least an hour had gone by) I disconnected the apparatus and took the suspected acid out to be tested using copper wire. However, there was no reaction and instead the liquid only appeared to clean the wire. The solution did not turn blue, indicating the presence of copper ions, and no NO2 gas was produced. Suspecting that there was still mostly hydrogen peroxide in the graduated cylinder I added a small amount of manganese oxide. This did confirm that the liquid still was mostly peroxide. I then conducted the experiment again making sure that I was following the exact procedure described in the video and again I yielded the same disappointing results. I am unsure how it did not work since the NO2 was clearly being created.

One note on the hydrogen peroxide used: I got the 15% by carefully evaporating off (using a heating pad) 3% stabilized peroxide. However, even if I had managed to decompose all of the peroxide, the NO2 should still react with the water to create some HNO3.

Please let me know if anyone has any ideas what might have happened and if there are any other easy ways, other than the classic sulfuric acid / nitrate salt distillation, to synthesize nitric acid.


https://www.google.com/url?sa=t&rct=j&q=&esrc=s&...

woelen - 31-5-2016 at 23:00

Making NO2 from a KNO3/HCl mix and some metal is not the best thing to do. Expect only a little NO2. Even a small amount of NO2 may look like a lot due to its intense color.

For 10 ml of 50% HNO3 you will need quite a large amount of nitrate and copper metal. I am afraid that the efficiency of the method is low, maybe 20% or so of the nitrate reacts, the rest remains in solution. Besides that, a KNO3/HCl mix will give very impure NO2. I also expect ONCl and Cl2. These gases will make your produced HNO3 impure and you will end up with a dilute HCl/HNO3 mix.