Sciencemadness Discussion Board

Ascorbic acid smell when boiled with chlorate

print118 - 3-5-2023 at 10:45

Heloo,

So I tried to make a low explosive called "Crimson Powder" but with potassium chlorate as the oxidizer instead of potassium nitrate to test the sensitivity and all, since I can't really get nitrates from anywhere. The mix also uses ascorbic acid as a fuel. The preparation of the explosive calls for the recrystallization method, where we boil the all the ingredients (potassium chlorate, ascorbic acid and red iron oxide as catalyst) in water, in an attempt to make a fine powder and to mix the components together well to make it more powerful.

The weird thing was the smell of a bit of chlorine and maybe a cat urine? type smell when boiling. The chlorine probably came from impurities in the chlorate, since it was made with electrolysis but I don't know what could cause the cat urine type smell. The only thing I could find online that smelled like cat urine and was somehow related to ascorbic acid was ferulic acid, which is used in some vitamin C serums, but I don't really see how ferulic acid could form here. One chemical I found that could form from the oxidization of the ascorbic acid was dehydroascorbic acid, but that shouldn't have any smell.

I tested boiling the solution with only the ascorbic acid, but there was no smell. And when I added the chlorate it still smelled like nothing, though when I added the red iron oxide it started smelling after a few moments. I don't know if the iron oxide does something chemically, since it doesn't dissolve in water but I think it may just act as nucleation points to make the water boil, because the water was boiling only a little bit before adding the iron oxide (superheating?). Maybe whatever the odor causing chemical was was generated between the chlorate and ascorbic acid but it was such a small amount that I couldn't smell it?

Maybe someone can shed some light onto this?

Tsjerk - 3-5-2023 at 11:37

Heating chlorate with an acid and a fuel... Recipe for shit to go boom. Or at least whoosh. Never just swap compounds because they look the same, especially if one of them is a chlorate.

Boffis - 3-5-2023 at 12:40

Chloric acid is a weak acid and the free acid an oxidizing agent; ascorbic acid is a reducing agent. When chlorate acts as an oxidizing agent it is reduced to chloride ions. Chloride ions plus chloric acid give chlorine.

So when you add a chlorate to ascorbic acid ultimately chlorine is formed. DO NOT TRY mixing dry ascorbic acid with a chlorate! Given time it will spontaneously ignite or explode!

In aqueous solution chlorates can be used as oxidizing or chlorinating agents in an acid environment, depending on the substrate. So for instance chlorate + HCl will first chlorinate caffeine to 8-chlorocaffeine then oxidize it to dimethylalloxan and then destroy it completely depending on the concentration of alkali chlorate. Water is almost always used as the solvent since it is passive in these reaction but its heat capacity helps moderate the reaction. Mixing chlorate with an organic acid dry is a recipe for disaster. Certain transition metals are known to accelerate these reaction, notably manganese.

I am not sure how chlorine /chloric acid would react with ascorbic acid in detail but I did some experiments a few years ago on the black "humic acid" substance that is a by product of furfural preparation from pentoses. The black material is rapidly decomposed into a soluble yellow syrup from which I managed to extract several crystalline compounds but TLC shows that it is a very complex mixture and nothing I recovered was homogeneous. The mixture had a strong, harsh unpleasant smell all the same. Cat urine like I don't know since I have never kept cats. But given the nature of the reaction it is likely that you get a complex mixture of chlorinated, low molecular weight, aliphatic compounds.

B(a)P - 3-5-2023 at 13:02

If you are going to do this with chlorate you need to use an ascorbate salt. The chlorate version of your "crimson powder" is an impact sensitive and extremely flame sensitive mixture. You don't need the iron oxide, it is sensitive enough without it. It is also not storage stable. There was a recent post about it relating to reactive targets here.

print118 - 3-5-2023 at 13:24

Quote: Originally posted by Tsjerk  
Heating chlorate with an acid and a fuel... Recipe for shit to go boom. Or at least whoosh. Never just swap compounds because they look the same, especially if one of them is a chlorate.

Yeah it ignited on me once, because I let too much of the water boil off. It's easy to prevent if the slurry is just taken off the heat while a bit wet and into low heat ~60°C to let it evaporate without igniting. I've just heard some mixed things about chlorate, so decided to do my own testing.
Quote: Originally posted by Boffis  
DO NOT TRY mixing dry ascorbic acid with a chlorate! Given time it will spontaneously ignite or explode!

-----------------------------

Mixing chlorate with an organic acid dry is a recipe for disaster.


Quote: Originally posted by B(a)P  
The chlorate version of your "crimson powder" is an impact sensitive and extremely flame sensitive mixture. You don't need the iron oxide, it is sensitive enough without it. It is also not storage stable.

So far the mix doesn't seem as sensitive as people claim chlorates with organics to be. Sure this is probably an exception, but this mix is hardly sensitive. I've hit it with a hammer multiple times, also with nails and also grinded it in a mortar and pestle, but it hasn't ignited at all. The mix does appear to be heat sensitive though, a bit over 100°C and it will ignite. I've also been able to store a smallish amount ~5g outside for about a week without it igniting. Maybe all this is due to the small amount of mix, since I've never made more than like 6 grams at a time?
Quote: Originally posted by Boffis  
But given the nature of the reaction it is likely that you get a complex mixture of chlorinated, low molecular weight, aliphatic compounds.

So basically, only god knows what's in it. I wonder if how the reactions affect the end products properties, would it burn slower if the chlorate oxidizes the ascorbic acid or something?
Quote: Originally posted by B(a)P  
If you are going to do this with chlorate you need to use an ascorbate salt. There was a recent post about it relating to reactive targets here.

Why is, for example potassium ascorbate used? Is it safer somehow like storage, at least judging by the "White Viper" video it seems more sensitive, and more powerful than just ascorbic acid at the same time.

B(a)P - 3-5-2023 at 15:56

Quote: Originally posted by print118  



Quote: Originally posted by B(a)P  
The chlorate version of your "crimson powder" is an impact sensitive and extremely flame sensitive mixture. You don't need the iron oxide, it is sensitive enough without it. It is also not storage stable.

So far the mix doesn't seem as sensitive as people claim chlorates with organics to be. Sure this is probably an exception, but this mix is hardly sensitive. I've hit it with a hammer multiple times, also with nails and also grinded it in a mortar and pestle, but it hasn't ignited at all. The mix does appear to be heat sensitive though, a bit over 100°C and it will ignite. I've also been able to store a smallish amount ~5g outside for about a week without it igniting. Maybe all this is due to the small amount of mix, since I've never made more than like 6 grams at a time?
Quote: Originally posted by B(a)P  
If you are going to do this with chlorate you need to use an ascorbate salt. There was a recent post about it relating to reactive targets here.

Why is, for example potassium ascorbate used? Is it safer somehow like storage, at least judging by the "White Viper" video it seems more sensitive, and more powerful than just ascorbic acid at the same time.


I am guessing that your product has partly decomposed during mixing/boiling leaving you with less oxidiser and fuel the remainder being a mixture of CRAP, this is why you are seeing a less reactive composition (and accounts for the released chlorine and other odour). An ascorbate salt is used instead of the acid so that chloric acid is not formed. If potassium ascorbate is used then no reaction will occur during the mixing of the two compounds. Once this mixture is dried it will behave as described.
To test this theory you could try mixing a very small amount (less than 0.1 g) of finely powdered ascorbic acid with potassium chlorate without introducing any water, then test this mixtures properties compared to what you got when you mixed this with water. Re-read the post from Boffis before you try this.

print118 - 3-5-2023 at 22:41

Quote: Originally posted by B(a)P  
Quote: Originally posted by print118  



Quote: Originally posted by B(a)P  
The chlorate version of your "crimson powder" is an impact sensitive and extremely flame sensitive mixture. You don't need the iron oxide, it is sensitive enough without it. It is also not storage stable.

So far the mix doesn't seem as sensitive as people claim chlorates with organics to be. Sure this is probably an exception, but this mix is hardly sensitive. I've hit it with a hammer multiple times, also with nails and also grinded it in a mortar and pestle, but it hasn't ignited at all. The mix does appear to be heat sensitive though, a bit over 100°C and it will ignite. I've also been able to store a smallish amount ~5g outside for about a week without it igniting. Maybe all this is due to the small amount of mix, since I've never made more than like 6 grams at a time?
Quote: Originally posted by B(a)P  
If you are going to do this with chlorate you need to use an ascorbate salt. There was a recent post about it relating to reactive targets here.

Why is, for example potassium ascorbate used? Is it safer somehow like storage, at least judging by the "White Viper" video it seems more sensitive, and more powerful than just ascorbic acid at the same time.


I am guessing that your product has partly decomposed during mixing/boiling leaving you with less oxidiser and fuel the remainder being a mixture of CRAP, this is why you are seeing a less reactive composition (and accounts for the released chlorine and other odour). An ascorbate salt is used instead of the acid so that chloric acid is not formed. If potassium ascorbate is used then no reaction will occur during the mixing of the two compounds. Once this mixture is dried it will behave as described.
To test this theory you could try mixing a very small amount (less than 0.1 g) of finely powdered ascorbic acid with potassium chlorate without introducing any water, then test this mixtures properties compared to what you got when you mixed this with water. Re-read the post from Boffis before you try this.


I've tired that before with pretty finely powdered potassium chlorate, ascorbic acid (pure) and red iron oxide and it's not sensitive to friction or impact at all. I've been able to hit it with a hammer and grind it without it igniting. Though like the recrystalliazed mix, it is pretty sensitive to heat. Both components have also been pretty dry, but I might try it again, but try drying it in an oven.

woelen - 4-5-2023 at 23:06

Try leaving out the ferric oxide and use dry material. Do NOT use more than a few hundreds of mg. Ignite the fine mix.
This may be interesting, just for the fun of the reaction and the demo-effect, but do not use this in larger quantities for any practical application, if you value your limbs!

Chlorate ion is a strong oxidizer in acidic aqueous solution. Ascorboic acid is quite acidic, sufficiently so to make the chlorate a strong oxidizer. Ascorbate and ascorbic acid are fairly strong reductors in aqueous solution, so you certainly will see a reaction between the chlorate and the ascorbic acid.

One of the reaction products is ClO2, which has a deep yellow color and a peculiar odour (quite different from the smell of ClO2). ClO2 reacts sluggishly in aqueous solution and also does not quickly hydrolyze. In the gas phase, this stuff is very dangerous and easily explodes! In your experiment, you will have only tiny amounts of ClO2 in the gas phase, enough to smell it, but not enough to make an explosive mix.

If you want to see this gas in a safe way, then take 200 mg or so of solid KClO3 and add a ml of concentrated HCl to it. Do NOT scale up! This will lead to formation of an intensely yellow gas mix, which consists of a mix of Cl2 and ClO2. The color of the gas mix is completely dominated by the intense color of ClO2, but the smell of the gas mix is completely dominated by the Cl2. Cl2 gas is very toxic, much more so than ClO2, so do this experiment outside. The intensely yellow gas can explode spontaneously, so only do this experiment in an open test tube. Do not store the gas mix in a capped bottle!

[Edited on 5-5-23 by woelen]

print118 - 9-5-2023 at 09:51

Quote: Originally posted by woelen  
Try leaving out the ferric oxide and use dry material. Do NOT use more than a few hundreds of mg. Ignite the fine mix.
This may be interesting, just for the fun of the reaction and the demo-effect, but do not use this in larger quantities for any practical application, if you value your limbs!
[Edited on 5-5-23 by woelen]

I tried 200mg and then more like a gram of the mix, which I dried for multiple hours to ensure dryness. The mix burned faster than if I had just mixed the chlorate and ascorbic acid together normally, I also grinded the mixture every now and then with a mortar and pestle while drying to ensure a fine and dry powder. Still this mix was not sensitive to impact from hammer or nail, though heat still ignited it well.

I was wondering why you say to only use more than a few hundred milligrams? This specific mix isn't super sensitive or something, though some chlorate mixes definitely are. Is it just a general rule for chlorate mixes that they are sensitive?
Quote: Originally posted by woelen  
Chlorate ion is a strong oxidizer in acidic aqueous solution. Ascorboic acid is quite acidic, sufficiently so to make the chlorate a strong oxidizer. Ascorbate and ascorbic acid are fairly strong reductors in aqueous solution, so you certainly will see a reaction between the chlorate and the ascorbic acid.

One of the reaction products is ClO2, which has a deep yellow color and a peculiar odour (quite different from the smell of ClO2). ClO2 reacts sluggishly in aqueous solution and also does not quickly hydrolyze. In the gas phase, this stuff is very dangerous and easily explodes! In your experiment, you will have only tiny amounts of ClO2 in the gas phase, enough to smell it, but not enough to make an explosive mix.
[Edited on 5-5-23 by woelen]

The "Crimson Powder" originally uses potassium nitrate as the oxidizer, wouldn't that also react with the ascorbic acid in solution or do they not react for some reason? And also what would be the reaction equation for the chlorate ascorbic acid reaction is solution? I can't seem to find anything referencing the production of ClO2, or maybe I'm just bad at googling.

woelen - 9-5-2023 at 10:26

Working with mixtures of strong oxidizers and fuels (reductors) always has a certain risk associated with it, and when the oxidizer is a chlorate salt, then risks are higher. For that reason, I strongly advise not to experiment with more than a few hundreds of mg in a single batch. If things ignite or explode, then the damage will not be too large, although with a few hundreds of mg, you already can have quite some painful fingers, due to burns or a small blast injury.

Nitrate ion in aqueous solution only is marginally strongly oxidizing. Nitric acid only is strongly oxidizing, when it is concentrated. This is because at high concentration, you have HNO3 molecules, and not nitrate ions. When the HNO3 splits in ions (nitrate and hydrated hydrogen ions), then its oxidizing power strongly diminishes. Chlorate ion, also when present as ClO3(-) ion, is quite a strong oxidizer at low pH. So, in aqueous solution, I do not expect any reaction between nitrate ions from KNO3 or NaNO3 and ascorbic acid. Concentrated nitric acid, however, certainly can react violently with ascorbic acid.

print118 - 9-5-2023 at 12:22

Quote: Originally posted by woelen  
Working with mixtures of strong oxidizers and fuels (reductors) always has a certain risk associated with it, and when the oxidizer is a chlorate salt, then risks are higher. For that reason, I strongly advise not to experiment with more than a few hundreds of mg in a single batch. If things ignite or explode, then the damage will not be too large, although with a few hundreds of mg, you already can have quite some painful fingers, due to burns or a small blast injury.

On the danger of chlorates, why isn't my mix too sensitive? Everywhere I look chlorates are always said to be very sensitive and prone to self-ignition when mixed with organics but my mix kind of contradicts that on this occasion. One would assume the chlorate and ascorbic acid mix to be rather sensitive, since it has an acid combined with a chlorate but I can't get it to easily ignite on impact, even when fine and dry. It also hasn't ignited on me spontaneously, at least not yet. I just don't know why, since based on the assumption of chlorates this should be a sensitive mixture. I also do appreciate you telling me what to do to be safe, but I would like to figure this out.

Oh, and sorry if I'm pushing you a bit but do you have the source or reaction for the production of chlorine dioxide in the reaction? It probably does exist based on the smell, but I'd like to see the actual reaction to see how much of it is produced.

woelen - 9-5-2023 at 23:31

Here follows an experiment I did several years ago with NaClO3 and conc. HCl: https://woelen.homescience.net/science/chem/exps/clo2/index....
This almost certainly also works with KClO3.

More recently, I did another experiment, in which I demonstrate the explosive properties of ClO2. For that experiment I used NaClO2, a compound, which can be used to prepare pure ClO2. Nowadays, sodium chlorate cannot be obtained anymore, but sodium chlorite, NaClO2, is a nice alternative for the experiment with ClO2.
https://woelen.homescience.net/science/chem/exps/ClO2_proper...

One of the issues with mixes of chlorates and fuels is their unpredictability. Things can go fine 100 times and then, apparently without any reason, the 101-th time things go BOOM. So, be careful and only use small amounts.
One thing you could try is just crunch solid ascorbic acid and solid KClO3 (separately!!!) in a mortar and then mix the two solids carefully (on a piece of paper, or in a petri dish, which is rocked around to mix the two crunched powders). In this way, you assure that not part of the chlorate already reacted with ascorbic acid in an aqueous solution. Use 250 mg of crunched KClO3 and 100 to 110 mg of crunched ascorbic acid. This is near optimal stoichiometry, assuming full oxidation to CO2 and H2O and formation of KCl.

unionised - 10-5-2023 at 02:31

A green little chemist
On a green little day
Mixed some green little chemicals
In a green little way.
The green little grasses
Now tenderly wave
O’er the green little chemist’s
Green little grave.