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? JJay - 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.happyfooddance - 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.mackolol - 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.Alkoholvergiftung - 20-7-2018 at 23:19
Why not use your calciumnitrate and Converse it with Soda to sodiumnitrate? It s easier to destill.JJay - 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. CobaltChloride - 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.clearly_not_atara - 21-7-2018 at 12:14
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]JJay - 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.
