RogueRose
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Making nitric acid with HCl vapor & NaNO3?
I tried my first nitric acid distillation with KNO3 + H2SO4 and it didn't turn out as well as I was hoping b/c the reaction flask was bubbling up so
badly as soon as some NO2 started to be generated that I finally gave up. I was only using about 40-50 watts (once boiling) in a heating mantle (1L
mantle & 1L RBF w/ ~350-400ml solution).
I need some dilute HNO3 to dissolve some silver and then use the nitrate for an electrolysis cell, so I did get some before the bubbling started
getting bad. I'd like to try making some more in a different manner and I was thinking of how people make very pure HCl by connecting a flask of
fuming HCl with a flask of distilled H2O, and I was wondering if something similar could be done to make nitric acid in this way.
The HCl I have is 31% so it can drop about 10% before reaching azeotropic level. If I placed plain NaNO3 in the flask which would have had distilled
water, would the HCl gas transfer over and convert it to HNO3 + NaCl? I'm thinking I could put a slight heating under the HCl, maybe 3-10w depending
on the size flask I use.
If this does work, I would think I could distill off the HNO3 + NaCl mix and get pretty high concentration HNO3. I'm wondering if this would work
better with no water in the receiving flask, with a little, or with a "moderate" amount. If it would work better with zero water I was thinking of
maybe using anhydrous CaCl2 as a dryer in between the flasks.
I'm interested in what you guys think and if you have any suggestions or if there's any glaringly obvious mistakes I'm not seeing here.
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Fyndium
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If hydrogen chloride is soluble in nitric acid, it should be doable in anhydrous conditions.
For a fact I can tell that dry HCl gas can be generated by dropping HCl into a heated flask filled with CaCl2 flakes and leading it through another
flask partially filled with CaCl2 to dry it. No need to waste precious H2SO4 as CaCl2 is sold in 25kg bags for 10€.
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unionised
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https://en.wikipedia.org/wiki/Nitrosyl_chloride
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Maurice-VD-3
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HCl 31% + NaNO3 will produce a mixture often called "aqua regia" which unfortunately does not contain any nitric acid. It contains a mixture of NaCl,
NOCl and Cl2. Because HCl and HNO3 react on each other : 3 HCl + HNO3 -> 2 H2O + Cl2 + NOCl.
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Bedlasky
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Quote: Originally posted by Maurice-VD-3  | | HCl 31% + NaNO3 will produce a mixture often called "aqua regia" which unfortunately does not contain any nitric acid. It contains a mixture of NaCl,
NOCl and Cl2. Because HCl and HNO3 react on each other : 3 HCl + HNO3 -> 2 H2O + Cl2 + NOCl. |
Aqua regia contains nitric acid, this reaction isn't that fast. If aqua regia immediately decompose in to NOCl and Cl2, it will be useless.
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zed
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Well, I used to generate HCl gas, but My approach was to slowly drip Concentrated H2SO4 onto Rock Salt. Thereby, not having foaming or run-away
problems.
My favorite Nitric Acid prep is by UC235. I haven't run it that way. But, it looks like a nice clean prep.
https://www.youtube.com/watch?v=DEEjNQN2dIQ&t=627s
The procedure you inquired about? I wouldn't.
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