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Author: Subject: HNO3 from Ca(NO3)2 + HCl - any reason it wouldn't work?
RogueRose
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[*] posted on 20-7-2018 at 18:59
HNO3 from Ca(NO3)2 + HCl - any reason it wouldn't work?


I'm trying to figure out a way to not deal with calcium sulfate when making HNO3 from Ca(NO3)2 and I was thinking that using HCl would balance the equation and give CaCl2 + HNO3 but I don't know what happens when HCl and HNO3 mixes as that is what aqua regia is and IDK if it seperated via distillation.

I was thinking that I could use the 32% HCl to dissolve the nitrate then distill it off and I guess I should use an excess of nitrate so that there isn't any HCl left in the liquid.

In another thread someone suggested using NaHSO4 instead of sulfuric acid and add both dry then distill, I'm wondering if the compounds would mix evenly enough to get a proper reaction especially with the nitrate being prilled.

Is there anything to be aware of or a reason the HCl route wouldn't work?
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JJay
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[*] posted on 20-7-2018 at 19:10


HCl might work, but there could be significant amounts of hydrogen chloride in the product. You can test it with aqueous silver nitrate and see if it produces a precipitate.



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happyfooddance
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[*] posted on 20-7-2018 at 19:41


I think at every molar concentration of acid either HCl is more volatile, or water, so you would get mostly those.
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mackolol
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[*] posted on 20-7-2018 at 23:00


With Muriatic acid it won't work as Hcl is gas and its way more volatile than hno3. Hcl boils at much lower temperature so you will get only azeotropic hcl/water. With nahso4 you need such high temperatures as 240C. The best way to nitric acid is with sulphuric acid even if it has smaller strength (pKa -3) than nitric (pKa -3.33) its way less volatile because its oxide (so3) is liquid in room temp so it easily replaces nitric acid from its salt. You can aldo try making nitric acid from acid which salt isnt soluble in water. For example Ca(NO3)2 + oxalic acid = Ca oxalate (which precipitates) and 2HNO3. But it isn't the easiest/cheapest way and i havent tried it.
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Alkoholvergiftung
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[*] posted on 20-7-2018 at 23:19


Why not use your calciumnitrate and Converse it with Soda to sodiumnitrate? It s easier to destill.
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JJay
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[*] posted on 20-7-2018 at 23:45


6 N HCl boils at 108 C... I'm not sure what temperature 6 N HNO3 boils at, but I'm guessing it is at around 110...

I think it's going to be very tricky to remove the HNO3 by distillation without removing substantial amounts of HCl with it. You're probably better off using phosphoric acid or sulfuric acid (and the suggestion to get rid of the calcium with sodium carbonate is a good one unless chipping a thick mass of corrosive plaster out of your flask sounds like a good time).

As a ridiculously expensive and completely impractical alternative, you could use silver nitrate instead of calcium nitrate with HCl.




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CobaltChloride
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[*] posted on 21-7-2018 at 01:44


This method wouldn't work at all. The nitric acic would oxidize the chloride ions making nitrosyl chloride, chlorine gas and nitrogen oxides. That's why everybody uses sulfuric acid when making nitric acid from nitrates.
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clearly_not_atara
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[*] posted on 21-7-2018 at 12:14


Quote: Originally posted by CobaltChloride  
This method wouldn't work at all. The nitric acic would oxidize the chloride ions making nitrosyl chloride, chlorine gas and nitrogen oxides. That's why everybody uses sulfuric acid when making nitric acid from nitrates.

Yeah, there's no way it works with hydrochloric I'm afraid.

I guess you could try phosphoric acid, but I don't imagine it'll be any easier to deal with than H2SO4.

Toluenesulfonic acid might work though. Triflic acid will.

EDIT: Re: JJay -- you could use hexamminecobalt trinitrate and HBr, maybe? But you will generate some bromine.

[Edited on 21-7-2018 by clearly_not_atara]




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JJay
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[*] posted on 21-7-2018 at 13:34


I'm pretty sure that a lot of these methods could be gotten to work to some extent (I'm pretty darn sure that silver nitrate works, and why would you be adding five mole equivalents of HCl per mole of calcium nitrate, anyway?), but the fact is that they are terrible methods.

Seeing as I have zero experience with aqua regia, I am going to shut my mouth now.

[Edited on 21-7-2018 by JJay]




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