Myc
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Isopropyl nitrite to sodium nitrite
Hi all,
I'm trying to make sodium nitrite (unavailable in my country) and am after some advice on effective hydrolysis of isopropyl nitrite (hereafter IPN)
with sodium hydroxide. I have tried a few things - I initially tried the reaction in an open beaker with aqueous NaOH solution with stirring and I
think most of my IPN just evaporated. In a sealed vessel at RT not much happens. Under reflux with ice water in the condenser the IPN disappeared but
I was left with mostly NaOH, but certainly some sodium nitrite in the mix, though far from a good yield. I also tried using a little 95% ethanol and
solid sodium hydroxide in a sealed container, and was able to retrieve about a 10% yield of sodium nitrite after recrystallising.
So far nothing worth pursuing... Any suggestions?
I have read through the various threads on sodium nitrite production and this route is often mentioned as a possible option though no details are
given. I have also had a bit of a read using Google scholar without much help.
Thanks team!
[Edited on 9-6-2022 by Myc]
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Fantasma4500
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yes i posted this in our grand nitrite thread
the basic math i cranked out was that 500g HNO3 turns into 100g NaNO2 and x amount of NaNO2 if you lead the NO2 formed from 500g HNO3 + Cu into NaOH
Cu(NO3)2 decomposes at about 220*C into - a much more appreciable amount of NO2, so this resource should not go forgotten
NaHSO4+nitrate salt may be utilized with some heating
as for the IPN to NaNO2- why not just try with solid NaOH? i think you might wanna set up for distillation and then tilt the whole thing upwards to
get as much of the IPN to drip back down into the flask again- and any that doesnt should go to the receiving flask, maybe plug the tip of the
condensing tube with something- this might once again just be because youre using very small amounts, as i see it using excess IPN should be the way
to make entirely pure NaNO2
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PirateDocBrown
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Sodium nitrite is unavailable? Where is this? It's used almost anyplace meat is preserved.
Phlogiston manufacturer/supplier.
For all your phlogiston needs.
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Myc
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Antiswat: Thanks. Happy to try solid NaOH as you say, but how would the setup you mention differ from reflux / sealed container?
PirateDocBrown: it's Australia. Strangely, I can walk into my local cleaning chemicals shop and buy 68% nitric acid, 98% sulfuric acid and 50%
peroxide. But I can't get Sodium nitrite or nitrate.
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Mateo_swe
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There must be a source of NaNO3 somewhere, its used for so much things.
But with no NaNO3 i would try the method Antiswat suggests.
HNO3 + Copper metal makes a lot of both NO2 and NO gases (toxic, do outside).
Lead these gases into NaOH and it should form NaNO2 and water.
I think NO2 and NO reacts to give N2O3 and this then react with NaOH to form the NaNO2.
Make sure no oxygen can interfere as this would make it to produce NaNO3 instead of NaNO2.
If im wrong about this please explain, but i think this should be possible and not so hard to do.
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AJKOER
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OK, Copper reacts with dilute HNO3 to create just NO.
Here is an interesting source "Oxidation of nitric oxide in aqueous solution to nitrite but not nitrate: comparison with enzymatically formed nitric
oxide from L-arginine" on how to possibly proceed to obtain just nitrite therefrom, to quote from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC47296/ :
"Nitric oxide (NO) in oxygen-containing aqueous solution has a short half-life that is often attributed to a rapid oxidation to both NO2- and NO3-.
The chemical fate of NO in aqueous solution is often assumed to be the same as that in air, where NO is oxidized to NO2 followed by dimerization to
N2O4. Water then reacts with N2O4 to form both NO2- and NO3-. We report here that NO in aqueous solution containing oxygen is oxidized primarily to
NO2- with little or no formation of NO3-."
Confirming comments per Wikipedia https://en.wikipedia.org/wiki/Nitric_oxide to quote:
"In water, nitric oxide reacts with oxygen to form nitrous acid (HNO2). The reaction is thought to proceed via the following stoichiometry:
4 .NO + O2 + 2 H2O → 4 HNO2"
Note: NO solubility: 0.0056 g / 100 ml (20 °C) and 0.0098 g / 100 ml (0 °C)
So, first step up a NO generator and be sure to purge all other gases and collect the NO over distilled water in which it should dissolve. Expose to
dissolved (or possible even gaseous) oxygen.
If you want NaNO2, per the equation above add 4 NaOH prior to the oxidation reaction. The removal/neutralization of HNO2 could help to move the
reaction to the right.
Also, an interesting work "Reaction of nitric oxide with hydrogen peroxide to produce potentially cytotoxic singlet oxygen as a model for nitric
oxide-mediated killing" here https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/0014-5793(93)80621-Z which claims that the action of dissolved NO in
H2O2 results in singlet oxygen with no mention of nitrite creation. However, as the half-life of singlet oxygen is about 45 minutes, in a few hours
only pure oxygen presence and possibly speculatively then nitrite creation in a closed reaction system.
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Lion850
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@Myc I am in QLD. “stump remover” which is KNO3 is readily available on eBay from local suppliers. Calcium nitrate is also on eBay and will give
you sodium nitrate in solution if reacted with table salt (and calcium chloride as ppt). And Science Essentials in Brisbane had sodium nitrite
available last i looked (and many nitrates). Vanbar imaging in Sydney sells nickel nitrate various quantities.
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B(a)P
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Vanbar Sydney is permanently closed unfortunately.
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SplendidAcylation
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Quote: Originally posted by Lion850  | | @Myc I am in QLD. “stump remover” which is KNO3 is readily available on eBay from local suppliers. Calcium nitrate is also on eBay and will give
you sodium nitrate in solution if reacted with table salt (and calcium chloride as ppt). And Science Essentials in Brisbane had sodium nitrite
available last i looked (and many nitrates). Vanbar imaging in Sydney sells nickel nitrate various quantities. |
Are you sure calcium chloride will precipitate? It is very soluble.
I would have thought it would be better to mix solutions of calcium nitrate with sodium hydroxide, sodium carbonate, or sodium sulfate, precipitating
the insoluble calcium hydroxide, carbonate, or sulfate.
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Fantasma4500
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| Quote: Originally posted by AJKOER |
So, first step up a NO generator and be sure to purge all other gases and collect the NO over distilled water in which it should dissolve. Expose to
dissolved (or possible even gaseous) oxygen. |
if you wanna make nitrite you dont oxidize the NO to NO2, then youre cutting your yields in half
isolating the gas is a problem on its own, check gas density and ponder how much gas you can collect and put to use- unless its of course continously
turned into NO2- its rather pointless because NaOH reacts with NO to form NaNO2
this thread should honestly just be thrown into our grand nitrite thread where we talked about this multiple times
NO2+ NaOH = NaNO2 + NaNO3
NO + NaOH = NaNO2
i dont quite believe Cu+HNO3 solely forms NO- in some quantity NO but nore pure, very doubtful on that. theres little online explaining the reaction.
i guess purging a reaction flask with CO2 or butane- maybe better. and then putting in.. actually one second ill do it just now in a reagent glass.
that was about 1 minute to produce that experiment, about 200mm long reagent tube, 1mL 70% HNO3 in
butane sprayed into the tube, droplets running down the sides of the tube, even contacting the nitric acid a bit, all oxygen completely purged from
the tube, small bits of copper wire was added and reaction happened within seconds producing brown fumes of NO2
but please do not oxidize NO into NO2 for the sake of producing nitrite. the gods of chemistry will curse your soul for that kind of mishap.
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Tsjerk
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| Quote: Originally posted by Antiswat |
that was about 1 minute to produce that experiment, about 200mm long reagent tube, 1mL 70% HNO3 in
butane sprayed into the tube, droplets running down the sides of the tube, even contacting the nitric acid a bit, all oxygen completely purged from
the tube, small bits of copper wire was added and reaction happened within seconds producing brown fumes of NO2 |
Dilute is the keyword
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Fantasma4500
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i have redone the experiment placing 1mL 70% HNO3 into a vial and maybe 10mL water with copper wires, it took long time to start, eventually i
discovered the solution had turned blue
i purged the vial with butane and put that into a 1000mL beaker which i also filled with butane and covered with aluminium foil
i guess it works, interestingly the NO didnt seem to wanna turn into NO2 very readily? maybe this reaction is more obvious at elevated temperature
the vial was also capped off with cotton wool. i guess it can work, however a method on our main nitrite thread has just been posted regarding calcium
formate and nitrate with great yields
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