making nitric acid

[hydraliskdragon]

The rubber stopper is completely covered with a teflon tape.

[frosch45]

Alright, its just that in your picture the stopper looks black, and teflon tape is white...

maybe the contrast just came out wierd

[iNow]

Alright, its just that in your picture the stopper looks black, and teflon tape is white...

maybe the contrast just came out wierd

 

Not always. While teflon tape is most commonly white, it is offered in many different colors (usually to signify different applications).

 

http://en.wikipedia.org/wiki/Thread_seal_tape

[hydraliskdragon]

Yes, I the hardware manager took me to the counter for teflon tape and there were four types of colour.

 

Anyways, should the distilation system be entirely self contained?

 

Since boiling liquids are involved, I am worried that my glasswares will shatter due to steam preesure.

[frosch45]

Hmm, well, now i know

 

Really, the more contained you can make it, the better. This stuff will kill or severly mangle. You can gamble if you want, but if I were you, i'd just get the stuff on ebay to contain it.

 

As per the boiling, you're right. You can't have it entirely contained or your glass will shatter, so in your setup, you need a joint like this

 

http://cgi.ebay.com/Distillation-adapter-with-vacuum-take-off-24-40-new_W0QQitemZ370106307778QQcmdZViewItemQQptZBI_Lab_Supplies?hash=item370106307778&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318

 

that will be there after the condensation is complete. This type of joint should lead to your recieving flask, and they are designed so that the air will come out from that flask instead of your condensing area. This just means though that you have to have a really really really cold condenser and recieving flask, otherwise, you will be breating scary stuff.

[cpazchem]

If it's any help, Sulfuric Acid is sold in Australia at 90% conc. for $40-$50 a liter. It is marketed as "Mo-Flo drain cleaner" in case they have it in England or America or wherever. It has "corrosion inhibitors", which means it is not chemically pure, however for the making of HNO3 the contaminants shouldn't have much effect. I use it for making esters mainly, and the purity of those seems to indicate that the "inhibitors" are not organic or volatile inorganic.

 

I do not recomend distilling H2SO4 unless you have the proper equiptment, i tried and it had worse effects on me than when i leaked hundreds of liters (quite literally, i produced 10moles, with a large reaction vessel at 70~80*C) of Cl2 from a high pressure Sodium Chlorate vessel! It was mainly the fumes that the distillation process releases that do the damage, my eyes stung beneith the goggles and my lungs burned after 1 breath.. DO NOT TRY IT!!

 

As for the whole NO2 dissolved thing.. all i can think is "where are you going to get the NO2?" as far as i no, the only real easy way to get it is to place copper (or a similar non-reactive metal) into conc. nitric acid, which kind of removes the need to make the NO2 in the first place.

Edited December 28, 2008 by YT2095
bad idea removed.

[jerryshizzle123]

Actually, NO2 can be made by heating a mixture of ammonium nitrate and sulfuric acid. If distillation isn't an option, the mixture could be strongly heated to yield nitric acid which would further decompose into NO2 and water vapor. From there, the gas could be extracted with a syringe and then dissolved in water.

 

However, nitric acid produced this way will have a low concentration and, unlike HCl, dissolving NO2 in water is freakin impossible.

[dede22]

Does someone know if this is right :

NaHSO4 + Ca(NO3)2→ CaSO4 + HNO3 + NaNO3

[cpazchem]

Thanx jerryshizzle123 for clarifying that for me.

 

um dede22, the equation balances, but that doesn't mean it will work. a good example is that of the solvay process. CaCO3 + 2NaCl → Na2CO3 + CaCl2. The reaction has no go power, so to speak, so it is achieved in a 5 step process. The reaction NaHSO4 + Ca(NO3)2→ CaSO4 + HNO3 + NaNO3 is probably the same, although im not entirely certain.

[jdurg]

Take a look at the enthalpy, entropy, and temperature that the reaction takes place in. Activation energy is also important. If the overall Gibbs Free Energy is positive, then it is not likely to happen. (Yes, this is a VERY simplistic assumption, but it works enough to be useful).

[UC]

Does someone know if this is right :

NaHSO4 + Ca(NO3)2→ CaSO4 + HNO3 + NaNO3

 

Even if it works you'll find that calcium sulfate is surprisingly and annoyingly soluble in nitric acid, increasing in solubility with HNO3 concentration.

[inuhbad]

In college it was easy to make what you needed in such a manner if you needed to... Using a condenser setup and keeping it completely sealed was the important parts.

 

Here in the US you can sometimes go into most auto-parts stores to buy a ~1 Liter bottle of Sulfuric Acid (used to refill lead-acid car batteries) in a 30% to 40% form for very low cost. Buy a couple of them, and then boil off the water. You have to be careful about the corrosion issues related to the fuming gas that's emitted as you get closer to a 'pure' concentrated form. Typically I would get yields in the 90 to 92% range, as that's about all I needed for my purposes.

 

In school if I needed Nitric Acid, I could just go to the supply room, sign out on the form, and take some 70% nitric acid for whatever I wanted. For personal projects outside of school it seems that Nitric Acid is next to impossible to find, and if you do manage to find some you aren't often able to be sure of its concentration.

 

I typically use Nitric Acid (diluted), Hydrochloric Acid (diluted), and metal salts to refinish old military surplus gun parts. Having uncertain concentrations, and then further diluting thatr concentration for my purposes usually creates too much variation in the quality of your metal finish from one 'batch' to the next. Often leading to discoloration, sometimes too deep of etching in the steel, and sometimes an insufficient amount of etching for the finish to 'take'.

 

By making your own Nitric Acid, though it has its own safety and impurity related problems, once tested, you can usually have a rather accurate assessment of its concentration. To some people it's the only way to get some, otherwise finding a source to purchase it is like trying to find hen's teeth in the US.

 

"Mo-Flo drain cleaner" in case they have it in England or America or wherever. It has "corrosion inhibitors", which means it is not chemically pure, however for the making of HNO3 the contaminants shouldn't have much effect.

Here in the US we have a similar cleaner, but the corrosion inhibitors, I forget their composition, but they actually ARE significant enough to have a negative effect on your experiments. Depending upon what you're trying to use the nitric acid for, it will throw off your results to an undesirable level. Edited January 13, 2009 by inuhbad

[jrayj]

I sucessfully managed to make a small amount of nitric acid from potassium nitrate (bought it) and sulfuric acid (boiled it down from car battery acid which I had from some hardware store). If you do it you need to be extremely carful and have a completly sealed ALL GLASS! setup. It started to eat through my rubber stopper which turned the yield green. I ended up stinkin up my laundry room which is another reason you should do this outside. If you do this MAKE SURE YOU HAVE THE PROPER EQUIPMENT!!!

[hermanntrude]

how do you know you made nitric acid? what test(s) did you do to confirm its purity?

[jrayj]

I didn't do any tests. What kind of tests could I do to assure that it nitric acid?

[macscigirl]

I think there was a thread/conversation about this, but it turned out that... eh, there was a problem with the forming of nitric acid or something.

 

I seem to remember this thread and I feel that they tried everything and ran into problems.

[hermanntrude]

if you carefully add a little sample of copper OUTDOORS WITH YOUR FACE A LONG LONG WAY AWAY FROM THE SAMPLE!!!! then you would see VERY VERY toxic brown NO2 gas given off.

 

There are probably safer tests but i dont know what they are other than things like mass spec and nmr

[macscigirl]

if you carefully add a little sample of copper OUTDOORS WITH YOUR FACE A LONG LONG WAY AWAY FROM THE SAMPLE!!!! then you would see VERY VERY toxic brown NO2 gas given off.

 

There are probably safer tests but i dont know what they are other than things like mass spec and nmr

 

I would listen to this dude

[jrayj]

Aight, will try the copper test this week and post the results. It seems to me that the manufacture of nitric acid is possible and quite easy with the proper equipment.

[jrayj]

Ok I tried adding copper to my nitric acid and it worked, picture included for the skeptics.

[Marine12320]

Well i was reading this, and i have tried to make nitric acid before. I heated NH4NO3 in a test tube with a stopper connected by a hose to another test tube halfway full with water in a ice water bath. I didn't see any brown NO2 fumes, so i assumed what was coming out was N2O. I gave up after a little while, but when i tested the pH of the liquid, it was about 1.5. I dont know what i made, but i guessed it was nitric acid. When i put a piece of copper in it, it didn't react. I left it there for 3 days. It's still here and it's been in there for 4 days and it still hasn't reacted yet. Do you guys have any idea what i made if it isn't HNO3? Please reply.

[nitric]

You only make a few different NOx's doing that, you need H2SO4 to actually make nitric acid, i have done a few very small batches and in situ. nitration's using that reaction(commonly employed in the making of picric acid and trinitrotoluene and other nitrated aromatics) with KNO3 and H2SO4 to make KSO4 and HNO3.

[Theophrastus]

I was thinking that you could make the nitric acid, by decomposing a nitrate salt, by means of heat. This would form the metal oxide, as well as NO2. (Beforehand, I must stress that due to the dangers of NO2 gas, you must make sure that your apparatus is free of leaks. I generally use some kind of perfume, released in the main body of the apparatus, after which I wait several minutes, searching for an escaping scent, applying teflon plumber's tape if it is required (On occasion I've also made esters- purely for the fun of it of course: mmmm. pears.) Then NO2 is then bubbled through water, to form nitric acid. You can then store your newly made acid in a cool undisturbed place. As it is rather sensitive to light, use of tinted or opaque glass is recommended.

[hermanntrude]

this is another reaction i'd say is way too dangerous to try at home. If you've done it without hurting yourself consider yourself congratulated. If you havent, try to at least think about it first.

[Theophrastus]

What is it that makes the reaction dangerous? The NO2 gas, I can account for with full glass apparatus, and teflon plumbers' tape if necessary, but what else? Is there perhaps a large amount of heat produced? Some other danger?