Sciencemadness Discussion Board

Making Sulfuric/Hydrochloric Acid With Nitric Acid

Deathunter88 - 22-2-2015 at 00:01

Hello everyone,
Ironically for me, I can only acquire nitric acid at a cheap acceptable price. It is extremely hard for me to acquire concentrated sulfuric and hydrochloric acid. I am asking if there is a way to make those two acids from nitric acid?
Thanks.

TheChemiKid - 22-2-2015 at 06:53

You can make HCl by adding salt to nitric acid in stoicheometric quantities.

[Edited on 22-2-2015 by TheChemiKid]

Bert - 22-2-2015 at 07:07

There is a Sodium or Potassium metabisulfite process for making sulfuric acid using nitric acid or Hydrogen peroxide, but it requires an acid (usually hydrochloric, see above post) to react with the bisulfite, releasing SO2.

http://youtu.be/okvvD3-DF9U

Where in the world are you that nitric acid is available, but sulfuric and hydrochloric are not?

Chemosynthesis - 22-2-2015 at 07:09

Not exactly a feasible process, but you could theoretically mix nitric acid with a sulfate salt and try freezing out the sulfuric acid. Equilibrium is disfavored, but you are shifting it.

woelen - 22-2-2015 at 07:50

Quote: Originally posted by TheChemiKid  
You can make HCl by adding salt to nitric acid in stoicheometric quantities.

[Edited on 22-2-2015 by TheChemiKid]

This is not true, you will get aqua-regia, which decomposes to chlorine and nitrosyl chloride. HNO3 is not a good starting point at all for making HCl.

Making H2SO4 from HNO3 also will be very hard, I see no reasonable way.

If you want HCl, then you have the option of heating a mix of table salt and so-called pH-minus for swimming pools (which is NaHSO4). HCl is driven off from such a mix and can be dissolved in water.

For many experiments in aqueous solution, NaHSO4 is a suitable substitute for dilute H2SO4. If you need concentrated H2SO4, then you have to buy it, or maybe you can do something with electrolysis of copper sulfate, but the latter process is slow and tedious and will produce impure acid.

Bert - 22-2-2015 at 08:34

Woelen, what are the temperature parameters for the NaHSO4 + NaCl process?

Deathunter88 - 22-2-2015 at 22:59

Quote: Originally posted by Bert  
There is a Sodium or Potassium metabisulfite process for making sulfuric acid using nitric acid or Hydrogen peroxide, but it requires an acid (usually hydrochloric, see above post) to react with the bisulfite, releasing SO2.

http://youtu.be/okvvD3-DF9U

Where in the world are you that nitric acid is available, but sulfuric and hydrochloric are not?


I live in China, which means I need a permit to purchase conc. Sulfuric acid (it is expensive too at 12 dollars a pint). Conc. nitric acid is cheap (2 dollars a pint) so I wondered if there was a way to transform one into the other.