Sciencemadness Discussion Board

Sodium nitrite from iron oxalate and sodium nitrate

Antiswat - 5-6-2021 at 07:51

in the past i have decomposed NaNO3 at high temperature on stovetop but varying success, the process takes quite some time, an hour give or take and youre limited to small batches of 100g - again with varying outcomes

however, i have finally decided to try out a theorized idea from a fellow chemist

most of us know that iron oxalate decomposes into pyrophoric iron, nanoiron. this iron can react very vigorously, and iron oxalate decomposes like that at a very doable temperature, seemed like 200*C, and sodium nitrate melts just above that

the procedure was simple, small steel cup on butane camp stove burner, sodium nitrate in, melt, dump in some iron oxalate, stir.
it turns a solid rust color, indicating Fe2O3
normally decomposition of FeOx turns black, from Fe3O4, Fe3O4 can be oxidized into Fe2O3- first good sign.
it didnt take much time, maybe a minute for each bit of iron oxalate to decompose
the melt seemed to harden up once it was done reacting, while it was liquid with iron oxalate and NaNO3 in there

testing out the remaining sludge i get a pH of 10 indicating is well basic, i didnt math out any ratios so its possible i missed out on a lot of yield
i reacted some of the solution with 98% H2SO4 and it gave me some NOx and CO2
then some pieces of copper wire in, heated it, and it started slowly reacting

so my take is that there is Na2CO3, NaNO2 and NaNO3 in there, all at once

i later confirmed with a vasodilatory headache that there is NaNO2 in there, some milliliters of 70% H2SO4 was added to the 20mL of solution along with half a milliliter of isopropylnitrite- CO2 bubbles and vasodilatory fumes arised with their characteristic odor. the fumes were ignited and burned exactly like isopropylnitrite would

since i have a stash of NaNO2 im not gonna bother trying to make actual yields out of this, but the solution seperates quite well from the iron oxide, it would be easy to just decant it to get rid of most of the iron oxides

Alkoholvergiftung - 5-6-2021 at 08:05

Old Industrial book praises the reduction of Sodiumnitrite with FeO. It has the highes yield. FeO can simple be made by mixing Fe2O3 and Fe powder and heated in an airtight container. But it cant be stored because it oxidize fast. Should be used in the 24h after its made.

unionised - 5-6-2021 at 09:24

Just bear in mind that you are heating a mixture of a nitrate and a fuel.

Antiswat - 5-6-2021 at 09:53

yes correct, but this fuel does not give off any real smell, like charcoal would
and unlike lead or any other metallic fuel you have it readily at a very small particle size at the discount of it having to decompose into the fuel first

alkoholvergiftung- what pressures and particle sizes would that be? iron powder is kinda difficult because it would tend to oxidize, angle grinder steel dust would be a mix of iron/Fe3O4
a band saw would be easy way to get kgs of iron shavings- is FeO practical/available? could iron oxalate + Fe2O3 maybe create FeO? does FeO react with CO2 as formed by iron oxalate decomposition?

edit: adding patent/process for making iron powder
1. A process for preparing metallic iron powder having a spongelike structure, a total iron content of 97% minimum, a metallic iron (Fe°) content of 89% minimum, an oxygen content of 2.3% maximum, a Green strength of 4000-6000 psi, and a Fischer subsive size of 1.5-3.5, with a minimum of 70% of a size of -325 mesh and a maximum of 1.0% of a size of +100 mesh.
heating to boiling for 1-3 hours, an aqueous solution comprising 0.4-2 M of a solubilized ferric salt, 10-40 g/l of formic acid or sulfuric acid and 60-120 g/l of urea, thereby obtaining a precipitate,

FeCl2 + sulfuric acid + urea = iron powder?

then iron powder + Fe2O3 = FeO in a closed vessel, welded tight, how much pressure, what temperature?
FeO + NaNO3 = NaNO2 + Fe2O3 or Fe3O4? promising.

[Edited on 5-6-2021 by Antiswat]

Alkoholvergiftung - 5-6-2021 at 10:54

They only wrote throught high heating. NaNO3+3FeO = Fe3O4 +NaNO2.
Most other moethodes with melting needs an alkalyhydroxid present. Sodiumnitrate and Sodiumhydroxide, castironpowder molten for 6 hours.
This one is good: 2 NaNO3 +Ca(OH)2 + SO2 (airfree) = NaNO2 +CaSO4. Heat near sinter point.

For the FeO cant find the orginal manuscript but this one works with an wet methode.
Orginal in german
5 parts Ironoxide and 4 parts powdered iron are mixed with the 2-3 times amount of water and heated to the boiling point under stiring. The reaction emits an disgusting metallic smell and an Black colored mass is formed. After the gas formation does stop the reaction is complet.After cooling you must seperate the unreactet iron from the FeO. After filtering you dry it with hot air. You get an black lose powder.
Sorry for my bad translation but that are the steps.

Bedlasky - 5-6-2021 at 11:19

Antiswat: This procedure looks really good! I never thought about making pyrophoric iron in situ.

Alkoholvergiftung - 5-6-2021 at 11:37

"As reducing agent in present of an melting alkalihydroxid are usabel Sulfur,pyrit,FeS,Iron,FeO,Charol,Coke,".
They used often Formiat salts.
This reaction happens at lower temperature they dont write the degrees.
Instead of Formiate you could use CO too
NaNO3+2NaOH +CO = NaNO2 + Na2CO3 + H2O
Nitrates and Formates are heated in Vakuum without Alkali.

Maybe if you add to the ironoxalat sodiumhydroxide you get higher yields.

[Edited on 5-6-2021 by Alkoholvergiftung]

Antiswat - 5-6-2021 at 23:30

i know carbon monoxide can be made by decomposition of zinc oxalate. aha, another oxalate.

Thermogravimetric analysis has indicated that a convenient range for the study of
n(COO)2.2H2O dehydration is 120–300 °C, while for pyrolysis it is 320–400 °C.

im still very much interested in operating temperature/pressure for making FeO from iron powder and Fe2O3, Fe2O3 is quite damn useless in general.

could zinc oxalate and NaOH slowly heated up in a pressurized chamber be used to make sodium formate maybe, any by that formic acid relatively easily?

Alkoholvergiftung - 6-6-2021 at 07:34

I would buy formic acid. You can get it for cleaning bee hives. 60% and be carfull because its smell is more nasty than acetic acid. I would only wear an gas mask when handling it.
FeO could also be made from Fe2O3 with H2 reduction in an quarz tube so you can watch colour change.

[Edited on 6-6-2021 by Alkoholvergiftung]

Antiswat - 13-6-2021 at 00:04

yes i noticed the main part was reducing iron hydroxides using hydrogen gas at 600-900*C- completely unrealistic for the amateur chemist

however, iron oxalate decomposes to make FeO, so one could potentially decompose iron oxalate and give it a slight bit of oxygen to form the FeO and then mix that with NaNO3 and then react it like that
but i think i'd just stick to mixing FeOx with NaNO3
iron oxalate is both easy and rewarding to make

sodium formate could be very doable, i believe sodium formate could be made by decomposing zinc oxalate and dumping the carbon monoxide into NaOH, you would end up with some sodium carbonate too
however sodium formate seems soluble in ethanol, so you could make quite pure sodium formate from zinc oxalate at home like that

C2H2O4Zn = ZnO + 2 CO + H2O
155g zinc oxalate would produce 56g CO


which would produce 2 moles of sodium formate, 136g- theoretically
it would be advised to turn the carbon monoxide gas into very small bubbles for higher absorbtion rate

Bedlasky - 13-6-2021 at 08:23

Antiswat: Carbon monoxide doesn't react with NaOH.

S.C. Wack - 13-6-2021 at 10:39

Not in that way, but it certainly does react and no doubt there are many patents.

Once again it's a matter of doing things the right way instead of the way you feel like doing them, to get something done besides wasting time and money.

In 1855-6 Berthelot invented not only the famous preparation of formic acid from glycerol and oxalic acid, but formate from CO and alkalis (Ba(OH)2, KOH, K2CO3) as well.

KOH solution did absorb CO, quite slowly. Much better luck was had with moistened, heated alkali, but even this required some time. Ann. chim. phys. 46, 477 (1856) if you really want to know.

clearly_not_atara - 13-6-2021 at 15:53

since i have a stash of NaNO2 im not gonna bother trying to make actual yields out of this

Pardon my pessimism, but simply making a detectable quantity of nitrite by nitrate reduction without being able to isolate it probably the easiest part; it is less than halfway to a useful method. The presence of nitric acid tends to be a hindrance in the reactions that call for nitrous acid, and the separation of ions is not trivial:

[Edited on 13-6-2021 by clearly_not_atara]

Antiswat - 15-6-2021 at 08:37

Carbon monoxide reacts with sodium hydroxide to produce sodium formate. This reaction takes place over pressure, temperature 1200C−2000C and in the presence of a catalyst.

i didnt seem to have any issues with making isopropyl nitrite from the batch i just scrapped together, im sure there are instances where nitrate content is gonna be a big problem however.

Alkoholvergiftung - 22-6-2021 at 21:32

Nitrit from Copperacetat and Pottasiumnitrate. If you use Copperpowder you get more KOH.In German.

On the representation of nitrous acid potash; from Persoz.
Proust proved that one can produce nitric acid potash by vigorously glowing nitric acid potash at high temperature. Later Gay-Lussac learned about the composition of the salt and showed that during the operation an amount of oxygen escapes which is equal to two fifths of the oxygen content of the nitric acid contained in the salt used, and that there is a compound which cannot be isolated or cannot be represented by itself, namely nitrous Acid forms, which combines with the potash to form nitrous acid potash.

However, this method of presentation gives a very low yield of nitrous acid salts and requires repeated crystallizations to remove the undecomposed excess nitric acid.

Since the use of nitrous acid salts can be of importance, Persoz sought to find a means by which two fifths of its oxygen content could be removed from the nitric acid of the nitric acid to be used; his choice fell on copper. As is well known, Wöhler 30) gave an excellent method for the preparation of pure potash, according to which a mixture of 1 th. Saltpeter with 2 to 3 thln. metallic copper is heated in small pieces to make it red-hot. By means of a few modifications of this process, Persoz arrived at a very simple method of preparing nitrous acid potash, which yields a considerable amount of the salt, which can be obtained in fairly purity by a simple crystallization.

First of all, very finely divided metallic copper is prepared by distilling acetic acid copper oxide, and from this freshly prepared metal powder 2 equivalents, or even a slight excess, to 1 equivalent of saltpetre, are taken, according to the equation

2 Cu + KO, NO⁵ = 2 CuO + KO, NO³.

Persoz took 320 grm. Saltpeter and 200 grm. of the copper represented in the manner indicated.

To produce an intimate mixture, the saltpetre is first dissolved in the smallest possible amount of hot water, and then the copper is added, which is initially difficult to wet. When the mixture has become quite homogeneous, it is heated in a porcelain bowl or, better still, in a cast-iron pan in a sand bath, stirring constantly to prevent splashing. When the mass is completely dry, there comes a moment when, like a pyrophore, it catches fire and glows; when the burning is over, which lasts only a moment, the reaction has taken place; it is allowed to cool, the melt is treated with water, filtered and the nitrous acid salt is allowed to crystallize. If excess copper has been used, there is no nitrate and crystallized nitrite is immediately obtained, which is then melted and stored in well-closed bottles, since the salt is very hygroscopic. Any undecomposed nitric acid potash that is present is separated out by the first crystallization, as it is far less soluble than the nitrous acid potash. The copper oxide obtained as residue during the operation can, after proper washing, be used for organic analysis, at least for mixing with the organic substance to be examined, since, although very finely divided, it is nevertheless very dense and hygroscopic to a much lesser extent than through Obtained glow from nitric acid copper oxide.

It should be noted, however, that ordinary copper, even in a very finely divided form, would not be suitable for the above purpose, since if it were used | 76 | to bring about the intended reaction the temperature would have to be raised much higher, so that caustic potash would be obtained rather than nitrous acid potash; on the other hand, when using the copper prepared from the acetic acid salts, the reaction already occurs at 200 to 250 ° C.

[Edited on 23-6-2021 by Alkoholvergiftung]

macckone - 23-6-2021 at 07:38

Lots of good ways to reduce sodium nitrate.
The problem is always getting a pure product and not starting a fire.
Sugar is excellent at reducing sodium nitrate but it is also good at combusting in the presence of oxidizers.

Potassium nitrate doesn't take as long when using the heating method.
The real trick is purification. With potassium nitrite, removing the nitrate is simply a matter of dissolving in water.
The nitrite dissolves to a saturated solution, while the nitrate doesn't. You have to use excess but it works.
Don't ask me how to dry it though. If you need solid pure potassium nitrite, you may need to buy it and it is expensive.
Possibly drying it with toluene might work but I wouldn't count on it. The stuff is hygroscopic.

Alkoholvergiftung - 23-6-2021 at 07:53

I ve read that an alkohol water mix works for purification. The potassiumnitrite does disolve in it the potassiumnitrate not.

[Edited on 23-6-2021 by Alkoholvergiftung]

macckone - 23-6-2021 at 09:31

Yes but how do you dry it afterwards?
Potassium Nitrite is much more soluble in water than the nitrate and will absorb moisture from the air.

Alkoholvergiftung - 24-6-2021 at 05:22

Vakuumexsikkator with Calciumchloride. Dont know hwo hygroscopic Potassiumnitrite is.