Nitric Acid synthesis

[Eddie Zheng]

Hello, I need some nitric acid. What are some ways nitric acid is made. I have a whole lot of sodium nitrate and sulfuric acid, and I do have a decent amount of glassware that would be suitable for the experiment.

Thanks, Eddie

[ajkoer]

If the H2SO4 is pure and concentrated, react directly with the NaNO3 and distill off to get pure HNO3:

H2SO4 + 2 NaNO3 --> Na2SO4 + 2 HNO3

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If the H2SO4 is impure or not concentrated, start by making FeSO4 by dissolving some iron in H2SO4. Caution: Hydrogen gas is generated.

H2SO4 + Fe --> FeSO4 + H2

Now add to this solution NaNO3 and more H2SO4 per the equation:

6 FeSO4 + 2 NaNO3 + 4 H2SO4---->4 H2O + 2 NO + Na2SO4 + 3 Fe2(SO4)3

This is the so called ring test for Nitric acid. Now that we have NO, there are many paths to HNO3. Examples:

1. Capture the NO gas and mix with air to form NO2:

NO + 1/2 O2 --> NO2

2. React the NO2 in a series of water towers (this is the commercial process):

3 NO2 + H2O --> 2 HNO3 + NO

Alternate process, dissolve the NO2 in H2O2:

2 NO2 + H2O2 -->2 HNO3

Alternate process: The action of the strong oxidizer HClO on NO:

3 NO + 3 HClO + H2O --> 2 HNO3 +3 HCl + NO

Good Luck.

Edited June 20, 2011 by ajkoer

[ercdndrs]

Hello All,

I'm also interested in making nitric acid. I do have ammonium nitrate and sulfuric acid, but my acid is very impure (buffering agents and colliodal carbon).

So, I am thinking of trying this alternate route, requiring few special materials (get ammonium nitrate from disposable cold packs):

 

1) Electrolyse ammonium nitrate solution with copper anode:

2 NO₃^- + Cu(s) - 2e = Cu(NO₃)₂(aq)

2 NH₄⁺ + 2 H₂O + 2e = H₂(g) + 2 NH₄OH(aq)

NH₄OH(aq) =NH₃(g) + H₂O

 

2) Electrolyse again with graphite electrodes:

2 Cu(NO₃)₂(aq) + 2 H₂O = 2 Cu(s) + 4 HNO₃(aq) + O₂(g)

 

As far as I know copper will only react with concentrated or hot oxidising acids. I know sulfuric acid can be prepared in the same way as step 2 from copper (II) sulfate, so I am wondering if nitric acid can be produced this way and if this process will work in general.

 

Are there any problems with anything I've done here?

 

Thanks!

Edited June 30, 2011 by ercdndrs