Sciencemadness Discussion Board - Potassium Ferrocyanide from Potassium Nitrate and Iron Oxalate

Potassium Ferrocyanide from Potassium Nitrate and Iron Oxalate

RU_KLO - 29-8-2024 at 16:50

The idea was to test if Potassium Ferrocyanide could be made from Potassium Nitrate and Iron Oxalate.

I tried before with KNO3 + C + Fe, but it was pyrotechnic…. A lot of fumes and splashes ….
I got a yellow solution after filtering, but no ferrocyanide (it did not make Prussian blue.)

So after making pyrophoric Iron (by decomposing by heat) thought that it could be a viable to make the ferrocyanide with Iron Oxalate.

With this in mind:

Iron Oxalate adds the Fe + C (Iron being high reactive – because is very small)
Potassium Nitrate adds the K and N.
Iron Oxalate decomposes at: 320-360°C
KNO3 melts at 350°C (but decomposes at 400°C)

So for a test (I did not calculate stoichiometry – I just wanted to know if it would work)

In a small porcelain crucible added a random amount of KNO3 (a small tea scoop)
Put the crucible in an alcohol lamp flame and tried to get it melted. Stirred with a glass rod. First it became orange (like scales because the heating was in the bottom) This was done outside. Without proper heat control, some wind, it took some time to get some melted. (it was like sugar on heat)
Once it started to melt, added more or less half the quantity of Iron oxalate. Stirred. The mixture became hard rock brown, tried to stir it, but with no luck.
So I put the lid on the crucible. After 10 minutes I checked the crucible, the mixture was melted in the center, scraped the sides, to try to melt all. Somehow it worked. The mixture bubbled. Added some more iron oxalate. On adding the oxalate, more bubbles were produced.
Left it 10 more minutes with the lid put. When no more bubbling were produced, removed from heat.

A hard red brick (or iron oxide red) was in the crucible. Added some water to try to dissolve it. It dissolved easily.

Tried to filter it. It needed like 5 pass on the filter, to get a very light red solution (a clear solution was not obtained….). No yellow solution….
The bulk of the solution is decanting, because filtering is an PITA. I will try to reduce the water by boiling trying to get some Potassium ferrocyanide crystals.

For testing made a Iron Chloride solution from Iron (II) sulfate + CaCl2. (then I read that I could use directly Iron (II) sulfate…..)

On adding some drops of the FeCl2 to the solution obtained, the solution became light blue and then coagulated as seen on the picture.

So, I think I got some Potassium ferrocyanide.

I think that with better temperature control (350-360°C) this could be viable way (not pyrotechnic…)

Iron oxalate decomposes:
Gunter and Rennag have proposed that when ferrous oxalate is heated above 300°C the primary decomposition
FeC204 -> FeO + CO + CO2
takes place, and that this is followed by secondary reactions such as:
(1) FeO + CO -> Fe + CO2, explaining the formation of iron;
(2) 4FeO ->Fe3O4 + Fe, explaining the formation of Fe3O4 and Fe;
(3) 2CO -> CO2 + C, explaining the formation of carbon.
(Sorry did not copy where I got this….)

Now how much reagents should be used?
What will the stoichiometry be?
We need at least 6 Nitrogen, so maybe 6M KNO3 + 3M FeC2O4.

(errata: in the picture Iron Oxalate should be FeC2O4)

[Edited on 30-8-2024 by RU_KLO]

j_sum1 - 29-8-2024 at 17:29

This looks like an interesting idea.

I have quite a bit of iron oxalate. (Collected from student experiments because Fe(II) + oxalic acid is an excellent quantitative precipitation reaction for teaching stoichiometry.) I have a cast iron crucible with a lid and plenty of KNO3. And I need some more potassium ferrocyanide. I am going to have to give this a try.

RU_KLO - 30-8-2024 at 03:08

Bad news....
The next morning checked and the flocculent precipitate was turned red, meaning that the blue precipitate is not prussian blue but an iron salt. (Maybe iron hydroxide) Checked the ph from the original solución and is highly alkaline. Probably KNO3 transformed into KOH.

j_sum1 - 30-8-2024 at 03:58

With those two reagents, the yield will be low. You just don't have enough carbon for the iron present. And the red colour is more indicative of ferricyanide.

I would not be in too much of a rush to confirm or reject your result. Prussian blue is strongly coloured and will show even if a minute amount is present. But with unbalanced stoichiometry, who knows what else is in the mix. There could be any number of things that could destroy the prussian blue.

It seems to me you need an additional source of nitrogen and carbon. Perhaps urea.

Anyway, the concept is interesting.

DraconicAcid - 30-8-2024 at 09:41

I'd suggest a more reducing source of nitrogen. Urea, as j_sum1 said, or any kind of amino acid/protein.

RU_KLO - 30-8-2024 at 11:03

thanks,

could also possible to add potassium carbonate as source of carbon and Potassium?

(I would not add directly carbon, because of pyrotechnics)
or there is no need?

Potassium carbonate + Urea are used to make KOCN

Also; I have done this outside, but what are the dangers of Cyanide poisoning (as HCN / cyanide salt?)
The process of Fe Oxalate + KNO3 did not fume - of course if you cant see it, does not mean it not there.
Also contamination on the crucible or hardware used?

DraconicAcid - 30-8-2024 at 11:18

When I say add nitrogen-containing organic compounds, I mean INSTEAD of the potassium nitrate, not in addition to.

RU_KLO - 30-8-2024 at 13:31

But the problem is that at the temperature needed to decompose iron oxalate (350°C) urea is already decomposed as cyanuric acid (and also close to it's sublimation point). The good thing about KNO3 is that it's a liquid at that temp.

Random - 15-9-2024 at 06:15

Blood should be tested as starting material.

It contains Carbon and Nitrogen.

Blood. Potassium Hydroxide. Iron.

...

clearly_not_atara - 15-9-2024 at 21:47

You might want more electrons than are available in iron oxalate. I think that ferrous acetate might be a good candidate. The resulting equation is nearly electron-balanced:

30 KNO3 + 24 FeC4H6O4 >> 5 K2CO3 + 19 FeCO3 + 5 K4FeC6N6 + 42 CO + 72 H2O

By contrast, the equation with oxalate is a little weird:

18 KNO3 + 61 FeC2O4 >> 3 K4FeC6N6 + 3 K2CO3 + 101 CO2 + 29 Fe2O3

That's a theoretical maximum of 5% of the input iron being incorporated into ferrocyanide.

[Edited on 16-9-2024 by clearly_not_atara]

bnull - 15-9-2024 at 22:13

Here go some observations. Any of them may happen to be wrong; I'll be receiving some oxalic acid this week and may verify that myself anyway.

The first thing I noticed is that there's too much oxygen in the mixture. The equations you show for the decomposition of iron oxalate are OK for iron oxalate alone. With a good source of oxygen (KNO₃) in the mix, Fe becomes FeO or (preferably) Fe₂O₃, and C and CO are oxidised to CO₂. One possible reaction is $$10~FeC_2O_4 + 6~KNO_3 \rightarrow 5~Fe_2O_3 + 20~CO_2 + 3~K_2O + 3~N_2.$$ This explains the bubbling of the melt (liberation of carbon dioxide) and the apparent formation of the bluish precipitate after addition of iron (ii) chloride (one of those layered iron hydroxides). It also appears that there was some unreacted nitrate^*, given the easy dissolution.

On the other hand, to make ferrocyanide from only iron (ii) oxalate and potassium nitrate, one would have $$61~FeC_2O_4 + 18~KNO_3 \rightarrow 3~K_4[Fe(CN)_6] + 29~Fe_2O_3 + 104~CO_2 + 3~K_2O,$$ which means about 38 g of oxalate^** for 7 g of nitrate. Since you were interested in feasibility rather than stoichiometry, the best I can do is stay sitting on the fence but with my legs swinging to the "no". Maybe it works with the right stoichiometry.

We can improve the process by adding something to take up those extra oxygen atoms. Carbon can be used, although the reaction is quite pyrotechnic-looking. The reaction is $$2~FeC_2O_4 + 12~KNO_3 + 29~C \rightarrow 2~K_4[Fe(CN)_6] + 21~CO_2 + 2~K_2O,$$ with the advantage that all iron is consumed and there would be no colloidal oxides to filter off. A slight excess of nitrate ensures that no carbon is left. The substances should be powdered and throughly mixed and the mixture ignited in small portions. Yes, it looks pyrotechnic after all.

We can also solve the problem of too much oxygen by using urea and potassium carbonate in place of nitrate. One advantage of using urea is that it is capable of dissolving many salts when slightly above its melting point (see, for example, R. E. D. Clark, Urea as Solvent). I suggest two possible reactions:
$$3~FeC_2O_4 + 14~(NH_2)_2CO + 6~K_2CO_3 \rightarrow 3~K_4[Fe(CN)_6] + 8~CO_2 + 28~H_2O + 5~N_2$$ and $$2~FeC_2O_4 + 6~(NH_2)_2CO + 4~K_2CO_3 + 5~C \rightarrow 2~K_4[Fe(CN)_6] + 7~CO2 + 12~H_2O.$$

The first consumes about 55% more urea than the second but avoids carbon residues after the reaction and makes it easier to stir. For both reactions the substances are pulverized and throughly mixed, and heated slowly enough so urea melts without excessive decomposition.

Blood and other ex-living matter residues were used in the old process described in Von Wagner's Manual of Chemical Technology (https://archive.org/details/manualofchemical00wagnuoft/page/...).

*: And possibly some nitrite,$$2~FeC_2O_4 + 3~KNO_3 \rightarrow Fe_2O_3 + 4~CO_2 + 3~KNO_2.$$
**: I assumed a molar mass of 160 g/mol (about arithmetic mean) because you didn't tell if it was the anhydrous or the dihydrated form.

Edit: Ninja attack again.

[Edited on 16-9-2024 by bnull]

Random - 16-9-2024 at 03:50

Historically, the compound was manufactured from nitrogenous organic material, iron filings, and potassium carbonate.[7] Common nitrogen and carbon sources were torrified horn, leather scrap, offal, or dried blood. It was also obtained commercially from gasworks spent oxide (purification of city gas from hydrogen cyanide

...

When you heat Blood. I wonder how the decomposition process goes. Those Nitrogenous compounds which are present when you heat it. I wonder what are those compounds.

j_sum1 - 16-9-2024 at 04:54

How would cyanuric acid go as a source?
(I have a two kilo bag.)

RU_KLO - 16-9-2024 at 09:20

Quote: Originally posted by bnull

We can also solve the problem of too much oxygen by using urea and potassium carbonate in place of nitrate. One advantage of using urea is that it is capable of dissolving many salts when slightly above its melting point

[Edited on 16-9-2024 by bnull]

Regarding adding carbon, tried - not in this setup, but similar -, but as soon as carbon is added, everythinh becames pyrotechnic.

Urea + potassium carbonate is another route I would try, but its the cyanate route:
(I think I got this from a SM post- regretfully did not keep the link)

synthesis and purification:

pour 10g urea and 11,5g K2CO3 into crucible
-> heat slowly with burner (H2O, CO2 and NH3 fumes evolving)
-> powder gets dry
-> apply more heat (NH3 fumes evolving)
dont heat to strong!
-> a clear molten mass shoud be in your crucible
-> let cool and crush to powder

->solve powder in min. amount of water
->add ACETIC ACID until no more CO2 evolves
->add two 2x EtOH (by volume)
->put in freezer
->filter out KOCN
->rinse with EtOH (CH3COONa is removed)

KOCN is prepared by heating urea with potassium carbonate at 400 °C:

2 OC(NH2)2 + K2CO3 → 2 KOCN + (NH4)2CO3
The reaction produces a liquid. Intermediates and impurities include biuret, cyanuric acid, and potassium allophanate (KO2CNHC(O)NH2), as well as unreacted starting urea, but these species are unstable at 400 °C

From there to check the possibility of making ferrocyanide from cyanate.

first making prussian blue, and then potassium ferrocyanide (from prussian blue)

From this paper it seems that maybe it could be done in the same process:

In this work, we synthesized Prussian Blue (PB) by pyrolysis of nitrogen-rich organic compounds and ferric/ferrous salts in the presence of alkali metal salt in inert atmosphere at high temperature, which was completely different form popular method based on the reaction of ferric ions and ferrocyanide ions. By exploring the history of Prussian Blue and some research results, we proposed a possible mechanism to explain the formation of Prussian Blue. The mechanism is as follows: Firstly, carbon, nitrogen and oxygen element in the mixture were transformed to cyanate by the catalysis of alkali metal species. With the increasing of temperature, organic compounds decomposed to release reducing gases such as H 2 and CO and eventually formed carbon materials. The reducing gases reduced part of Fe 3+ to Fe 2+ and the carbon reduced the cyanate to cyanide. So Prussian Blue was formed by cyanide, Fe 3+ and Fe 2+ . The most import substance in the process is the alkali salts and a key intermediate product namely cyanate is proposed.

So an idea:

1) Carbon, nitrogen and oxygen element in the mixture were transformed to cyanate by the catalysis of alkali metal species
this will be done with Cyanuric Acid (or Urea) + K2CO3 (as stated before)

gases such as H 2 and CO and eventually formed carbon materials
Maybe this could be made by Iron Oxalate

1) 2 OC(NH2)2 + K2CO3 → 2 KOCN + (NH4)2CO3

2) At 220-370C:
3 Fe2C2O4 -> Fe3O4 + 4CO + 2CO2

(The first effect with the minimum at 200 °C is ascribed to the process of dehydratation and partial decomposition of dehydrated ferric oxalate to ferrous oxalate: 3Fe2(C2O4)3·5H2O > Fe2(C2O4)3 + 4FeC2O4 + 15H2O + 4CO2. The second reaction step within the range of 220–320 °C is assigned to the decomposition of the rest of ferric oxalate to Fe3O4 and α-Fe: 2Fe2(C2O4)3 > Fe3O4 + Fe + 6CO + 6CO2. Finally, in the last reaction step (at about 400 °C), the decomposition of ferrous oxalate proceeds: 4FeC2O4 > Fe3O4 + Fe + 4CO + 4CO2

Maybe this is worth of trying: using sucrose for adding carbon
(watch out for candy rocket.....)

or try: pyrolisys of sucrose, urea, iron sulfate, potassium sulfate (check attached paper)

Then transform pussian blue to ferrocyanide....
"In 1752, the French chemist Pierre Joseph Macquer (1718–1784) first reported the preparation of Potassium hexacyanidoferrate(II), which he achieved by reacting Prussian blue (iron(III) ferrocyanide) with potassium hydroxide."

"Histoire de l'Académie Royale des Sciences …, § Mémoires de l'Académie royale des Sciences (in French): 60–77. From pp. 63-64: "Après avoir essayé ainsi inutilement de décomposer le bleu de Prusse par les acides, … n'avoit plus qu'une couleur jaune un peu rousse." (After having tried so vainly to decompose Prussian blue by acids, I made recourse to alkalies. I put a half ounce of this [Prussian] blue in a flask, and I poured on it ten ounces of a solution of nitre fixed by tartar [i.e., potassium nitrate (nitre) which is mixed with crude cream of tartar and then ignited, producing potassium carbonate]. As soon as these two substances had been mixed together, I saw with astonishment that, without the aid of heat, the blue color had entirely disappeared; the powder [i.e., precipitate] at the bottom of the flask had only a rather gray color: having put this vessel on a sand bath in order to heat the solution until it simmered, this gray color also disappeared entirely, and all that was contained in the flask, both the powder [i.e., precipitate] and the solution, had only a yellow color [that was] a little red.)"
https://en.wikipedia.org/wiki/Potassium_ferrocyanide#cite_no...

Attachment: a-possible-mechanism-behind-the-discovery-of-prussian-blue.pdf (480kB)
This file has been downloaded 167 times

bnull - 19-9-2024 at 09:02

Disclaimer: The equations below represent possible reactions, and do not preclude the existence of other pathways that lead to ferrocyanide starting from the same set of reagents.

@Random: Quite hard to say. The first step may be denaturation of proteins (albumin from serum) and partial decomposition of lipo- and glycoproteins (cell membranes); the last step, the formation of amines, whether simple or containing other functional groups, perhaps a Maillard. No hint as to what comes in-between, especially since blood is a very complex substance. It is possible that some research had been conducted on thermal decomposition of blood, but I haven't found none so far.

@j_sum1: Cyanuric acid seems better than urea, with the right proportion of C to N. In combination with potassium nitrate and potassium carbonate, with and without carbon^*, we have the possible reactions:
$$45~FeC_2O_4 + 2~(CHNO)_3 + 12~KNO_3 \leftrightarrow 3~K_4[Fe(CN)_6] + 3~H_2O + 78~CO_2 + 21~Fe_2O_3,$$
$$6~FeC_2O_4 + 4~(CHNO)_3 + 24~KNO_3 + 63~C \leftrightarrow 6~K_4[Fe(CN)_6] + 6~H_2O + 51~CO_2,$$
$$13~FeC_2O_4 + 6~(CHNO)_3 + 6~K_2CO_3 \leftrightarrow 3~K_4[Fe(CN)_6] + 9~H_2O + 32~CO_2 + 5~Fe_2O_3,$$
$$2~FeC_2O_4 + 4~(CHNO)_3 + 4~K_2CO_3 + 5~C \leftrightarrow 2~K_4[Fe(CN)_6] + 6~H_2O + 13~CO_2.$$

*: I'm still using carbon as reducing agent for convenience; other substances can be used, the best being those that don't leave solid or liquid residues on oxidation.

@RU_KLO: Perhaps you could use the pyrotechnicity to your advantage. Mix the reagents and shape the mixture into thin cylinders, for example, and ignite them inside a crucible or other suitable container. You would need no external heating. Should be safe enough in small quantities.

The procedure given in the paper makes use of sealed tubes in a tube furnace. I'm not sure it will work with an open vessel.

Sucrose may generate lots of smoke on decomposition; it releases ~59% water, or 11 moles of water for each 1 mole of sucrose. It'll probably make a mess, with smoke and sputtering. It may work, who knows.

Random - 22-9-2024 at 09:45

@bnull\\\ I have done dry distillation of Sucrose if I remember correctly in 2011

It gives this caramel colored liquid. Actually, if I remember correctly it gave this yellowish liquid and there was this brownish caramel colored oily liquid on top of this yellow liquid

Edit

You know those Furfural compounds... also Furan

...

I remember how I left this Sucrose being heated on Stove as I was distracted by one person and lots of smoke appeared

I wonder how I managed to not have this smoke as I did dry distillation

[Edited on 22-9-2024 by Random]

[Edited on 22-9-2024 by Random]

Edit

Also look, Dippel Oil

[Edited on 22-9-2024 by Random]

Screenshot_20240922_195320_Chrome.jpg - 259kB

Screenshot_20240922_195309_Chrome.jpg - 388kB

Screenshot_20240922_195246_Chrome.jpg - 614kB

bnull - 22-9-2024 at 12:09

There is one difference here: it is not pure sucrose. It is sucrose plus iron oxalate plus potassium nitrate (fireworks!) or potassium carbonate.

Edit: By the way: bleurgh! They used Dippel's oil as a medicine. You gotta be kidding...

[Edited on 22-9-2024 by bnull]

Random - 23-9-2024 at 09:16

Quote: Originally posted by bnull

There is one difference here: it is not pure sucrose. It is sucrose plus iron oxalate plus potassium nitrate (fireworks!) or potassium carbonate.

Edit: By the way: bleurgh! They used Dippel's oil as a medicine. You gotta be kidding...

[Edited on 22-9-2024 by bnull]

It says that Dippel's oil also contains Nitril.

If that is true then FerroCyanide can be made from it.

...

Also this stuff like Garum. You know. This Fish stuff.

...

Dry distillation of Fish. Dry Distillation of this Fish sauce which is almost Garum... which is precursor to Garum

...

Nitrile

...

Benzoic Acid and Urea gives BenzAmid

From Benzamid you can get BenzoNitril

From Nitril you can get FerroCyanide. It should be possible.

...

Also IsoCyanid.

DraconicAcid - 23-9-2024 at 09:43

Quote: Originally posted by Random

From Benzamid you can get BenzoNitril

From Nitril you can get FerroCyanide. It should be possible.
Also IsoCyanid.

I'm not an organic chemist, but I seriously doubt it. That carbon-carbon bond is pretty strong. How are you going to break it without just hydrolyzing the benzonitrile back to benzoic acid?

clearly_not_atara - 23-9-2024 at 11:06

Oxamic acid is another particularly interesting possibility in this case because it offers a neutral oxygen balance with no other ingredients:

4 KNH2C2O3 + Fe(NH2C2O3)2 >> 6 CO2 + 6 H2O + K4Fe(CN)6

Unlike the other equations, this one is very easy to balance. Oxamic acid is produced by the thermal dehydration of monoammonium oxalate (NH4C2O4H) at around 230 C.

Random - 23-9-2024 at 12:16

Quote: Originally posted by DraconicAcid

Quote: Originally posted by Random

From Benzamid you can get BenzoNitril

From Nitril you can get FerroCyanide. It should be possible.
Also IsoCyanid.

I'm not an organic chemist, but I seriously doubt it. That carbon-carbon bond is pretty strong. How are you going to break it without just hydrolyzing the benzonitrile back to benzoic acid?

Benzonitrile is a nitrile that is hydrogen cyanide in which the hydrogen has been replaced by a phenyl group

...

|||Acetonitrile has a free electron pair at the nitrogen atom, which can form many transition metal nitrile complex

...

---

Actually, after doing some research. It is said that PolyAcryloNitrile gives as much as 30% HCN when \\\dry distilled

...

What do you think about PolyAcryloNitril?

DraconicAcid - 23-9-2024 at 12:21

Quote: Originally posted by Random

Benzonitrile is a nitrile that is hydrogen cyanide in which the hydrogen has been replaced by a phenyl group
Acetonitrile has a free electron pair at the nitrogen atom, which can form many transition metal nitrile complex

These are nitrile complexes. Not cyano complexes. Nitriles bond through the nitrogen, not the carbon, and the C-C bond is not weakened.

Random - 23-9-2024 at 14:27

Quote: Originally posted by DraconicAcid

Quote: Originally posted by Random

These are nitrile complexes. Not cyano complexes. Nitriles bond through the nitrogen, not the carbon, and the C-C bond is not weakened.

I thought in terms of Carbon and Nitrogen containing compound.
In terms of using the compound for heating it with KOH and\or whatever it is needed.

But PolyAcriloNitril seems like a nice choice.

[Edited on 23-9-2024 by Random]

bnull - 23-9-2024 at 15:32

@clearly_not_atara: It seems good. No nitrates, no reducing agents, no insoluble oxides or charcoal to remove.

Quote: Originally posted by Random

I thought in terms of Carbon and Nitrogen containing compound.
In terms of using the compound for heating it with KOH and\or whatever it is needed.

@DraconicAcid, it seems that @Random was not so random after all. There's a paper (Berkoff et al., The Reductive Decyanation of Nitriles by Alkali Fusion; see attachment) describing the removal of the cyano group by heating with KOH, with cyanate as one of the products.

Quote:

We now report a practical, novel method for the reductive decyanation of nitriles using alkali fusion and the application of this reaction in the preparation of two important anti-histamines, chlorpheniramine and brompheniramine.

It may not work for benzonitrile. Even so, it was a nice shot.

Attachment: berkoff1980.pdf (198kB)
This file has been downloaded 72 times

Random - 23-9-2024 at 21:33

@bnull

Regarding aromatic nitril I have researched yesterday. I don't like using ChatGPT as primary source.

But I did this quick research about replacing Aromatic Ring with Hydrogen. ... And also about protection of Cyanid group.

Trimethylsilyl chloride, that is what is said to protect it.

Also I saw this suggestion about this strong reducens... was it strong reducens action on Aromatic Ring.

Then I saw this topic about CyanoBoroHyd...

...

Everything should be possible. It should be more deeply investigated.

...

But PolyAcryloNitril. This needs to be researched.

10%-30% HCN produced by PyroLysis. And it is not so uncommon Poly.

Edit:

I mean. Why would you even deal with this high temperature stuff if you can just use PolyAcryloNitril.

[Edited on 24-9-2024 by Random]

j_sum1 - 25-9-2024 at 19:42

I have some experiment results. (Notable because I actually got to spend some time in the lab.)
Both based on cyanuric acid.

Experiment 1 – 350°C reaction between Iron oxalate, potassium carbonate, cyanuric acid and carbon

2FeC2O4 + 4C3H3O3N3 + 4K2CO3 +5C --> 2K4[Fe(CN)6] + 13CO2 + 6H2O

Heated 12g of FeC2O4 and other reagents in stoichiometric quantities over a butane burner in a cast iron crucible with loose lid.
Powdered mixture became fluidised releasing lots of gas. When temperature exceeded about 330°C a thick tarry substance was formed with continued bubbling. Above 350°C there was an odour of ammonia offgassing. Temperature was lowered and reaction continued until bubbling ceased.
Result was a solid cake which was scraped away with some difficulty with water. Filtering the suspension gave a dark residue that looked like FeO. Filtrate was cloudy and rust coloured and slightly acidic. No evidence of either ferrocyanide or ferricyanide. My suspicion was that the carbon did not react at all and that much of what I had obtained was merely decomposition products. This led me to attempt a lower temperature route.

Experiment 2 – Reaction between Iron oxalate, potassium carbonate, cyanuric acid and oxalic acid in aqueous suspension

FeC2O4 + 2C3H3O3N3 + 2K2CO3 + 5H2C2O4 --> K4[Fe(CN)6] + 14CO2 + 8H2O

Suspension was formed with 7.75g of FeC2O4 and other reagents in stoichiometric quantities in 150mL of water in a 500mL RBF. Mixture was stirred and refluxed for 12 hours.
Product contained quite a lot of solid that settled out. Filtering gave an acidic solution that was a lime-yellow colour (concidentally, the exact same shade as a K3[Fe(CN)6] solution I had on hand - at least to my eyes.)
Product was tested with Fe3+ and Fe2+ solutions and did not behave as either ferrocyanide or ferricyanide. Presence of oxalic acid could potentially have affected results. Further testing after neutralising revealed trace amounts of Fe(III) in solution but not the desired product.

Clean up suggested that very little of the iron oxalate or cyanuric acid had reacted. I suspect that my solution was mostly a ferro-oxalato complex in oxalic acid.

I am prepared to give up on iron oxalate as a starting material for obtaining ferrocyanide.

[Edited on 27-9-2024 by j_sum1]

Random - 26-9-2024 at 08:48

j_sum1

If you are willing to do it. Try PolyAcryloNitril.

I would love to see result.

I would do it myself and post the result but I currently don't have the means to perform it where I am.

...

It is sais that it should be heated withoit oxygen presence. Then it produces according to DATA as much as 10%-30% HCN.

It might be that you could take test tube and put a stopper and bubble the gaseous product into KOH

And then react this Cyanide to produce FerroCyanide

Edit

Polyacrylonitrile is also known as polyvinyl cyanide

[Edited on 26-9-2024 by Random]

clearly_not_atara - 26-9-2024 at 09:34

I thought the whole point of this thread was to make ferrocyanide without using HCN gas. There are many easier ways to make hydrogen cyanide, but the disadvantage is that they all produce hydrogen cyanide.

Random - 26-9-2024 at 09:41

Quote: Originally posted by clearly_not_atara

I thought the whole point of this thread was to make ferrocyanide without using HCN gas. There are many easier ways to make hydrogen cyanide, but the disadvantage is that they all produce hydrogen cyanide.

It seems less scary when using PolyAcryloNitrile.

...

You know. Imagine being near a fire with this plastic burning. You would not even know it.

Also FireFighting.

Jenks - 26-9-2024 at 17:51

Keep in mind that ferrocyanide itself decomposes into cyanide, carbon and iron when heated.

Random - 26-9-2024 at 19:25

One route to Cyanide could be also this route as it is inside Biological process. Is it Amgygdalin?

You know. There was this VIDEO on YouTube.

Dissolving Gold with Cherry Pits

...

I believe you need to get used to Cyanid. Of course it is scary if you deal with Concentrat.

...

You can use Dilluted SOLUTION. Turn Dilluted SOLUTION into FerroCyanid.

clearly_not_atara - 26-9-2024 at 20:30

Quote:

Imagine being near a fire with this plastic burning. You would not even know it.

Cyanide is highly flammable and rapidly consumed in a flame. The amount released would be much smaller than through pyrolysis. Even so:

https://journals.lww.com/euro-emergencymed/fulltext/2013/020...
"HCN from fire smoke is probably the most common cause of acute cyanide poisoning in developed countries"

Any use of ionic cyanides is very dangerous. Avoiding it is definitely worthwhile.

j_sum1 - 26-9-2024 at 21:29

Quote: Originally posted by Random

j_sum1

If you are willing to do it. Try PolyAcryloNitril.

I don't have any, so that is not really an option.

Realistically, I will probably just buy some potassium ferrocyanide to replenish my stocks. The appeal was the possibility of a straightforward 1 pot synthesis using things I have a surplus of.

Random - 26-9-2024 at 21:45

You know. I was reading those Insectronics and Amphibionics books according to my personal memory inside 2006.

Was it 2006.

...

You know. You could build a simple Robot to do it for you.

It is a novel idea. Why risk your life with a toxic substance if you cam do it from distance.

It is a little bit offtopic but

...

You know. Things are changing.

In 2010 when I joined here the world did not have so many options.

Edit:

Getting experienced and courageous but not foolish in handling what we could mark as extremely dangerous substances is a process in itself.

Ontopic. A discussion could be why it is not possible or ehy it was not in this case possible to perform this from KNO3 and FeOxalat.

...

There were more how I could say ideas regarding this topic.

[Edited on 27-9-2024 by Random]

Edit2:

Processes behind various chemical reactions should be more deeply investigated. Which we could call mainstream scientific community is too...

Here I was interrupted in writing this post.

Between everything unlisted if they were capable they would also be here.

[Edited on 27-9-2024 by Random]