# Question About Poor mans Nitric



## MetalMan76 (Mar 3, 2011)

What is the highest level of concentration I can get making poor mans nitric without distillation?


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## lazersteve (Mar 3, 2011)

It depends on the source of your reagents, the amount of water you use, and your skill at performing the reaciton.

Theoretical maximum would be around 68%, realistically you can expect between 30-50%.

Steve


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## MetalMan76 (Mar 4, 2011)

Thanks for the reply Steve

Actually, I use your recipe for making Nitric. But instead of Sodium nitrate, I use Ammonium nitrate. Some batches are better than others but the reaction seems to be shorter then expected. I guessing I'm getting somewhere between 30 and 50%. If I increase the amount of nitrate and decrease the amount of water, would that help with the concentration?


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## lazersteve (Mar 4, 2011)

For refining 35% is the desired percentage in most cases. 

This is known as 50/50 nitric acid because 35% nitric acid is made by mixing 1 part 70% nitric acid with 1 part distilled water, so 1 liter of 50/50 is 500 mL 70% HNO3 + 500 mL H2O, hence :50/50.

Adding more nitrate won't increase the concentration unless you add more 98% concentrated sulfuric acid. 

Careful distillation is the only way I know of to increase the concentration of your nitric acid after it is made. You can try using less water in your reaction, but I'm not sure how well the reaction will work this way. 

Also the reason I choose sodium nitrate in the recipe is due to the unique solubility curve of sodium sulfate. From around 40C down to 0C the solubility of sodium sulfate decreases by a factor of 10 which lends itself well to crystallization and easy removal with out distillation. Ammonium sulfate does not demonstrate this same solubility curve and therefore more of the nitrate remains unconverted to nitrate in the cold solution resulting in weaker nitric acid.

4.9 grams of Sodium sulfate will dissolve in 100mL of 0C water.
70.6 grams of ammonium sulfate will dissolve in 100mL of 0C water.

As you can see, more ammonium sulfate remains in your solution when cold, so less nitric will have been made by the action of freezing. The nitric acid is formed when the sulfate crystallizes out and leaves the hydrogen atoms from the H2SO4 behind in the cold solution to form nitric acid with the nitrate portion of your salt which stays in the solution.

2NaNO3 + H2SO4 + H2O --> -5C --> 2HNO3 + Na2SO4 + H2O

I've never tried the cold nitric recipe without the water, it may work, it may not. The biggest problem is that your crystals will be a mixture of sulfate and undissolved nitrate due to the lack of water in the reaction. 

Steve


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## godofwar (Mar 4, 2011)

MetalMan76 said:


> Thanks for the reply Steve
> 
> Actually, I use your recipe for making Nitric. But instead of Sodium nitrate, I use Ammonium nitrate. Some batches are better than others but the reaction seems to be shorter then expected. I guessing I'm getting somewhere between 30 and 50%. If I increase the amount of nitrate and decrease the amount of water, would that help with the concentration?



i have used ammonia nitrate and switch to a potassium nitrate.... mainly because it was easier to come by and concentration and performance do vary between the 2.... i ordered up some sodium nitrate tech grade specifically due to Steve's posts and info that can be found every where. 

if you have a problem finding it you can order it here...
i previously bought it a $2.83 for 2 pound bag-man it jumped up in a matter of weeks

http://www.amazon.com/Sodium-Nitrat...ie=UTF8&s=miscellaneous&qid=1299244549&sr=8-2

but i know someone here has a good web store better than amazon

oh and on a side note: LaserSteve big thank you to you man


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## element47 (Apr 23, 2011)

When one makes nitric acid in this way: From sodium nitrate and concentrated sulfuric acid, presumably there will be sodium and sulfate ions in solution. My question is, can the presence of these be ignored? If so, can it be ignored for silver dissolution, and, can it be ignored for AR creation with HCl? (separate questions)


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## Joeforbes (Apr 26, 2011)

godofwar said:


> MetalMan76 said:
> 
> 
> > Thanks for the reply Steve
> ...




I buy my Sodium Nitrate from dudadiesel - http://www.dudadiesel.com/search.php?query=nitrate&affiliate_pro_tracking_id=17:29:

Though, I'm sure there is a site better than that still. I like ordering from them though, fast delivery and each time it's been between a little, and a LOT heavier than what I ordered. Once it was just under 11 lbs when I ordered 10lbs.


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