Sciencemadness Discussion Board

HNO3 from kno3+hcl

underground - 7-1-2022 at 12:24

I got some Sr/Ba carbonate and i was thinking to make them nitrates. I got some kno3 and hcl so i was thinking to do some nitric acid from this reaction. I am for the need of kcl too so nothing is going to be wasted. My idea is to use an excess of kno3 to hcl so no hcl will be in the solution, in theory at least. No distillation, just mix kno3 and hcl. I really don't mind if there are some potassium salt as long as i want to use them in pyrotechnics for colored flames. What i am considering is if any of the left over salts like SrCl2 or BaCL2 salts are hygroscopic. I have no idea how hygroscopic are so they may ruin the compositions later on.

P.S. I am aware of barium toxicity.

[Edited on 7-1-2022 by underground]

Tsjerk - 7-1-2022 at 14:02

Will not work, NOCl will form.

Fulmen - 7-1-2022 at 16:48

At best you will end up with a mixture of KNO3 and Sr/BaCl2. You will have to consult the solubility tables to figure out if they can be separated.

underground - 8-1-2022 at 01:54

Hmmm. What if i made some calcium nitrate from ammonium nitrate and calcium hydroxide. Then add sulfuric acid to calcium nitrate. Calcium sulfate is mostly insoluble.

macckone - 8-1-2022 at 09:04

Quote: Originally posted by underground  
Hmmm. What if i made some calcium nitrate from ammonium nitrate and calcium hydroxide. Then add sulfuric acid to calcium nitrate. Calcium sulfate is mostly insoluble.


That is a standard method.
Usually it is distilled but you could dissolve it in water to extract it.
Not sure what you are trying to do but without distillation you are unlikely to get it concentrated enough to do more than react with carbonates.

Tsjerk - 8-1-2022 at 12:08

When you just want a red/purple flame, you could make SrCl2 with excess SrCO3 with HCl. Filter the excess SrCO3 and add a solution of KNO3. Now you can boil down to a volume where mostly KCl crystalizes. The strontium nitrate will have a KCl contamination, but potassium is moderately purple, which in combination with strontium might not be too much of a problem. The chloride might help with the flame coloring of strontium, but I never understood how that works exactly.

Don't know how a mixture of barium and potassium would behave.

[Edited on 8-1-2022 by Tsjerk]

clearly_not_atara - 8-1-2022 at 12:59

I don't know about sulfuric acid and calcium nitrate; the CaSO4 ppt is renowned for ruining glassware. I think it would make more sense to distill off nitric acid from a solution of KNO3 in sulfuric acid. Possibly, even KHSO4 could be used.

Another option is toluenesulfonic acid. The advantage is that p-TsOH precipitates from strongly acidic solutions; it is only soluble when dissociated, cf:
http://www.sciencemadness.org/talk/viewthread.php?tid=3132#p...
https://pubs.acs.org/doi/abs/10.1021/ie403228w

So p-TsOH might be regenerated from the salt "leftover" by treatment with concentrated hydrochloric acid, which allows you to solve the initial problem of KNO3+HCl >> HNO3. I'm not sure if you can avoid bubbling HCl gas in order to accomplish this, though.

p-TsOH is prepared by heating dilute sulfuric acid with an excess of toluene as described by Nicodem:
http://www.sciencemadness.org/talk/viewthread.php?tid=11878#...

But if you only need one "batch" it's easier to use H2SO4.

underground - 9-1-2022 at 05:34

Quote: Originally posted by Tsjerk  
When you just want a red/purple flame, you could make SrCl2 with excess SrCO3 with HCl. Filter the excess SrCO3 and add a solution of KNO3. Now you can boil down to a volume where mostly KCl crystalizes. The strontium nitrate will have a KCl contamination, but potassium is moderately purple, which in combination with strontium might not be too much of a problem. The chloride might help with the flame coloring of strontium, but I never understood how that works exactly.

Don't know how a mixture of barium and potassium would behave.

[Edited on 8-1-2022 by Tsjerk]


I will try it, thanks. With barium, i don't think so it will work since the solubility of barium chloride is almost identical to KCL. On the other hand, strontium chloride is much more soluble than KCL.

brubei - 9-1-2022 at 06:17

i can send low concentration HNO3 if you need small quantity