Nitric acid from nitrate

[rbennett07]

Hello. I'm new to this seemingly awesome forum.

 

So if i take a nitrate salt and put it in H2SO4 it will yield HNO3? Will this occur just by dropping (slowly inserting, solution of nit. salt maybe, since the acid is so exothermic) the salt into the acid? Will they react on their own? Of course I'd also set up an ice bath.

 

When it comes to sulfuric acid, can liquid fire drain cleaner be used, in terms of purity? It says it contains concentrated sulfuric acid, and it gives all the wonderful warnings about how it can erupt violently from the drain anytime etc. so i thought id verify this.

 

I get the impression that HNO3 is violently poisonus, but a whole lot stronger than HCl? I've been playing with muriatic acid alot lately and I imagine its MUCH stronger than that, but i don't know. Can I even store the nitric acid that is made for an extended period of time? Enlighten me if you don't mind.

[woelen]

Welcome to the SFN forums and hopefully you will have a good time over here .

 

You can indeed make HNO3 from a nitrate salt (most suitable are KNO3 and NaNO3), by adding the solid to concentrated H2SO4. You, however, need to distill the acid and that is not such an easy task. Nitric acid is corrosive like hell and it will eat your distilling apparatus away, when it is not an all-glass apparatus (possibly with teflon joins). With a dry salt and concentrated H2SO4 you obtain red fuming nitric acid. That is a solution of NO2 in HNO3. It is amazingly corrosive and very hard to use in a home lab. Boiling temperature will be somewhere between 80 and 90 C.

 

You could also make more pure HNO3 (besides having water in it) by mixing some water with the H2SO4 (be careful: always add acid to water very slowly, while stirring). Mix 1 part of water with 2 parts of acid. To that, you add the solid salt and then you do the distillation again. Now you get less decomposition and the acid is much cleaner. This can yield between 50 and 70% acid, with only a small amount of NO2 dissolved in it. This probably is what you want. Also here, however, the distilling apparatus needs to be all-glass with teflon joins. Boiling temperature will be somewhere between 120 and 130 C.

 

As you see, making HNO3 at home is possible, but not easy. It must be done with the greatest care.

[RyanJ]

Hi there! Welcome to SFN

 

Here are some other threads that may prove interesting (relating to the production of nitric acid)

 

http://www.scienceforums.net/forums/showthread.php?t=5944

http://www.scienceforums.net/forums/showthread.php?t=16973

 

Cheers,

 

Ryan Jones

[jdurg]

In regards to storing HNO3, that can be done but you need a properly ventillated acid storage cabinet preferably with a special section for nitric acid. Over time, HNO3 will decompose and give off very corrosive nitric oxides. These oxides will tend to nitrate most anything which isn't something that you want happening. This is why in labs and universities the HNO3 is stored in it's own inert section of the acid cabinets with plenty of ventillation.

[woelen]

Jdurg, this decomposition is VERY slow, when the acid is stored in the dark. Now 22 years ago, I purchased a brown glass bottle of 65% HNO3, and I put this in a box somewhere in a dark place in my parent's home. Lateron, I moved and forgot about the bottle of acid. Recently, I found that same bottle of HNO3 again in its box. It was covered by some dust and there was a very thin layer of white frost-like stuff around the neck of the bottle. I rinsed away all stuff and let the bottle dry. The acid in the bottle still is concentrated, the volume of acid still is the same (almost 1 liter, and it also was, when it was put over there), and the liquid still is perfectly colorless. It has survived cold winters, and hot summers. I was really surprised to see that nitric acid remains good for so long.

 

So, I think, that as long as the acid is stored in a glass bottle with a thick inert plastic cap, that it can be stored at an ordinary home without problems. But, the cap must be very good. The bottle I have had such a sturdy thick red cap, with a teflon white disk inside. These are well-known (at least over here in Europe) in bottles in which corrosive chemicals are stored.

[bob000555]

it would be easier to make HNO3 by pumping NO3 trou watter

http://en.wikipedia.org/wiki/HNO3#Synthesis_and_production