Mark Van Adium
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Nitrous acid production & shelf life
So I'm making up some liebermann reagent (Sulfuric acid and sodium nitrite) and thinking about its shelf life.
When I mix it up there's often undissolved solid which almost looks something that's precipitated. If I heat it up then it dissolves and stays that
way.
However I'm aware that HONO isn't very stable and heating will be detrimental to this.
Would I be better just ignoring that solid? It looks like there is about 10% of the initial amount of nitrite.
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hissingnoise
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| Quote: |
However I'm aware that HONO isn't very stable and heating will be detrimental to this. |
Indeed! Nitrous acid has no shelf life to speak of and so should be generated in situ when needed?
Drugtesting, eh?
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Mark Van Adium
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Can it not even be stored refrigerated and sealed to give some sort of storage ability? I want to make a batch and leave a bottle at my friends' for
them to use.
[Edited on 7-2-2016 by Mark Van Adium]
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UC235
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Liebermann reagent is NOT nitrous acid. It is nitrosyl sulfuric acid dissolved in concentrated sulfuric acid. I'm unsure of the shelf life with proper
storage, but water would be extremely deleterious to it and it is quite hygroscopic.
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hissingnoise
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| Quote: | | Liebermann reagent is NOT nitrous acid. It is nitrosyl sulfuric acid dissolved in concentrated sulfuric acid. |
Don't know where you got that idea . . . ???
The solution is available as a kit, so presumably it has some shelf-life!
I was going to suggest you leave the measured reagents with your friend so that they can be mixed when needed . . .
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hive3
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I made up a batch 4 months ago and it still reacts consistently. Its in a small 10 ml dropper bottle.
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Mark Van Adium
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I tried some I bought about 2 months ago on some paracetamol and it gave a yellow reaction instead of the expected purple. Pure sulfuric acid gives no
colour on the same sample. Not sure what's going on but it's no use if it's temperamental.
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