Official pyrotechnics thread!

[jdurg]

Sulfur is used in black powder to create a more attainable energy flow for the reaction. If you just have KNO3 and C in your reaction, sure you can generate CO2 and N2 if the right ratio is achieved, but what will happen with the potassium? There needs to be something there to counter the potassium ion. By adding sulfur, you allow the formation of K2S in the reaction, and your overall reaction could then be 2KNO3 + 3C + S => K2S + 3CO2 + N2.

[woelen]

Sulfur is used in black powder to create a more attainable energy flow for the reaction. If you just have KNO3 and C in your reaction, sure you can generate CO2 and N2 if the right ratio is achieved, but what will happen with the potassium? There needs to be something there to counter the potassium ion. By adding sulfur, you allow the formation of K2S in the reaction, and your overall reaction could then be 2KNO3 + 3C + S => K2S + 3CO2 + N2.

Jdurg, I did the test, I was wondering what happens:

 

With KNO3 and C, finely powdered. The reaction is self-sustaining, but not as smooth as one would like. I took the melt and added some acid to it, and it bubbles a little and I saw small amounts of brown vapor, that must be due to NO2. So, I conclude that the mix contains at least some KNO2, also K2CO3.

I only took a mix of let's say 200 mg, it might be that in larger quantities the reaction proceeds smoother, but this small quantity needed to be relighted another time.

 

Next, I took KNO3, C and S, all finely powdered. When lit, this mix burns quickly and smoothly, however not violently (it's a huge difference, compared with the KBrO3 mix I also made, see other thread on KBrO3). After the reaction, I took the molten and again solidified mix and added some acid to it. Definitely, some H2S could be smelled, there was a smell of rotten eggs, but I hardly had any bubbling. This is not what I expected. If the molten solid was mainly K2S, then I would have had a lot of bubbling.

I did a counter experiment with some of my commercially obtained Na2S. This indeed bubbles vigorously, when 10% HCl is added.

So, I conclude that a small amount of K2S is formed, but the main products are different. I suspect most of the stuff formed is K2SO4, with only small amounts of K2S and K2CO3.

 

Have a look at this: http://en.wikipedia.org/wiki/Black_powder

 

Your reaction with K2S is mentioned, but another reaction with K2CO3 and K2SO4 is mentioned as well. The truth is even more complex, with a LOT of side reactions and one cannot give a good equation, representing all products of burning. This also is stated by the wikipedia article.

 

I just did this little research with my own chems out of curiosity. This simple reaction still has a lot of interesting features to be investigated.

[RyanJ]

I have a question regarding TNT. Ive always understood the reason it is so explosive is becasue the nitro and methly groups withdraw electron density from the bezenze creating weak bonds' date=' correct?

If so wouldn't a benzene with further more elctronegative groups added on be more effective or is this too impractical. e.g. tri flouro benzene if such a chemical exists?[/quote']

 

I'm not shure about this but doesn't Fluorine form stronng bonds with things? Would that compound be stable if it exists?

 

jdurg, woelen: Thanks for the explination but would Phosphorus work instead? Its a lot more reactive but I'm just wondering if it would work in a practical way?

 

Cheers,

 

Ryan Jones

[woelen]

I'm not shure about this but doesn't Fluorine form stronng bonds with things? Would that compound be stable if it exists?

 

jdurg' date=' woelen: Thanks for the explination but would Phosphorus work instead? Its a lot more reactive but I'm just wondering if it would work in a practical way?

 

Cheers,

 

Ryan Jones[/quote']

Yes, phosphorus works instead. Of course it must be red phosphorus, the white allotrope is so insanely toxic and also flammable, that cannot be used in pyrotechnic devices, although it is used (sadly enough) in white phosporous grenades in warfare.

 

Red phosphorous can be substituted for both the carbon and the sulphur. A composition with red phosphorous, however, is much more sensitive. With KNO3 as oxidizer, it can be used reasonably safely, but with KClO3 it simply is suicide to mix them in any appreciable quantity. I've done a simple experiment with KClO3 and red P. I took 50 mg of KClO3, put it on the ground and put approximately 50 mg of red P above it. I took a small wooden stick, attempting to mix the two chems (the red P was on top, I wanted them mixed). At the moment that I touched the small heap of chems and I moved the stick a little, the mix did WHOOSH with a very bright white flash and it was gone ! I knew how dangerous this mix was, that's why I only took such small amounts and also used the stick and did not pre-mix. However, it was awful to see it burn so violently with such a little agitation and such a poor mixing. I'm wondering what happens with a KBrO3/P mix (I might give it a try one of these days with 20 mg or so).

[RyanJ]

Yes' date=' phosphorus works instead. Of course it must be red phosphorus, the white allotrope is so insanely toxic and also flammable, that cannot be used in pyrotechnic devices, although it is used (sadly enough) in white phosporous grenades in warfare.

 

Red phosphorous can be substituted for both the carbon and the sulphur. A composition with red phosphorous, however, is much more sensitive. With KNo3 as oxidizer, it can be used reasonably safely, but with KClO3 it simply is suicide to mix them. I've done a simple experiment with KClO3 and red P. I took 50 mg of KClO3, put it on the ground and put approximately 50 mg of red P above it. I took a small wooden stick, attempting to mix the two chems (the red P was on top, I wanted them mixed). At the moment that I touched the small heap of chems and I moved the stick a little, the mix did WHOOSH with a very bright white flash and it was gone ! I knew how dangerous this mix was, that's why I only took such small amounts and also used the stick and did not pre-mix. However, it was awful to see it burn so violently with such a little agitation and such a poor mixing. I'm wondering what happens with a KBrO3/P mix (I might give it a try one of these days with 20 mg or so).[/quote']

 

That explains why its probably not used very much then!

So it cna be used with some oxadisers but not with others then? Hmm, interesting

 

I'm thinking the [ce]KBrO3[/ce] and [ce]P[/ce] mx would be quite unstable and very reactive, like you said in the other thread, [ce]KBrO3[/ce] is far more poweful than [ce]KClO3[/ce]

 

Cheers,

 

Ryan Jones

[woelen]

That explains why its probably not used very much then!

So it cna be used with some oxadisers but not with others then? Hmm' date=' interesting

 

I'm thinking the [ce']KBrO3[/ce] and [ce]P[/ce] mx would be quite unstable and very reactive, like you said in the other thread, [ce]KBrO3[/ce] is far more poweful than [ce]KClO3[/ce]

 

Cheers,

 

Ryan Jones

Yes, you are right. Red P can be used with some oxidizers (KNO3, KClO4, but YT probably can give more authorative answers on that), but even then it is not the reductor of first choice. In the Netherlands, the use of red P in consumer fireworks is prohibited and I see no real reason why you want to use it for that. But I'm quite sure, that if you look at pyro-books, that there will be compositions with red P in them, but again, here I would like to refer to the real pyro-experts.

[YT2095]

RP and KClO3 (aka Armstrongs mixture) has probably claimed as many fingers from K3wls as AP has done, it can ignite/explode entirely without warning or apparent provocation, naturaly made with KBrO3 instead, this situation would only become even more unstable.

there ARE some bonded mixture that have containd this in the past though, notably Match Heads, although now phosphorus sesquisulphide has replaced elemental Phos in most compositions. Armstrongs mixture is Still made in factories it goes into Caps for toy guns, even the industry that makes these is not without it`s share of disaster occuring.

[woelen]

I found a nice word of wisdom on Usenet:rec.pyrotechnics, and here follows my liberal phrasing of this:

 

Playing with KClO3 and red phosporous is like playing with a deadly poisonous snake. Playing with KBrO3 and red phosporous is like playing with a deadly poisonous snake, which is slightly pissed-off.

[YT2095]

LOL, I like it

 

if the mixture is kept wet and in tiny amounts it`s reasonably "Safe", it`s when it`s a fine powder form that you`re courting disaster, even diapering can trigger it, when wet and mixed with a binder and allowed to set, you can make perfectly good matches with it though

 

see: "Playing with matches" thread.

[jdurg]

Heh. When I first got my Red P for my element collection, I had a bunch of the stuff so I decided to experiment a little bit. I mixed it with a chlorine and oxygen containing compound and when struck with a hammer I scared the living bejesus out of my two cats.

[YT2095]

that same compound with Sulpher and Glucose will do exactly the same when treated like that too, even milligram amounts are perfectly deafening.

it`s considerably More stable with an Extra oxygen though, but still far from Perfect

[RyanJ]

that same compound with Sulpher and Glucose will do exactly the same when treated like that too' date=' even milligram amounts are perfectly deafening.

it`s considerably More stable with an Extra oxygen though, but still far from Perfect [/quote']

 

Really? Sulphur and glucose do the same thing? Thats nuts

 

YT2095: Sounds like the armstrong mix is pretty nasty stuff... And that the stuff they use in gun-caps? I always thought that was a gun powder mix but I always wondered why it was white and not black

 

Cheers,

 

Ryan Jones

[YT2095]

Really? Sulphur and glucose do the same thing? Thats nuts

 

yes really, it needn`t be Glucose either (I only use that as it`s a very fine mesh) the same works with icing sugar just the same.

[RyanJ]

yes really, it needn`t be Glucose either (I only use that as it`s a very fine mesh) the same works with icing sugar just the same.

 

I suppose the same thing would happen with Phosphorus and glocose too then.

 

Is it me or are the chemistry of Sulphur and Phosphorus are quite simmilar?

 

Also, is pure phosphorus used in any fireworks or the like? If yes then what effects does it make?

 

Cheers,

 

Ryan Jones

[YT2095]

yes the same thing would happen with phos and glucose too, only easier.

 

and yes Phos is used in pyrotechnic compostions as stated previously, caps for toy guns and party poppers are classed as Fireworks (indoors).

 

Sulpher and Phos do share a few similar traits, as do Alu and Mg, the comparison`s about the same too

[jdurg]

Really? Sulphur and glucose do the same thing? Thats nuts

 

YT2095: Sounds like the armstrong mix is pretty nasty stuff... And that the stuff they use in gun-caps? I always thought that was a gun powder mix but I always wondered why it was white and not black

 

Cheers' date='

 

Ryan Jones[/quote']

 

I don't think sulfur and glucose alone will make the 'KABOOM'. There's another compound that I had mentioned without naming which is involved too. We just aren't going to be naming the substance as we don't need some idiotic 'lee7 k3wler' kid making it and blowing his fingers off.

[RyanJ]

I don't think sulfur and glucose alone will make the 'KABOOM'. There's another compound that I had mentioned without naming which is involved too. We just aren't going to be naming the substance as we don't need some idiotic 'lee7 k3wler' kid making it and blowing his fingers off.

 

Yup, make sence.

The same people who you say speciafically DO NOT DO THIS as it explodes and then go and do it just for that reaosn and hurt or kill themselves or other people (Giving chemists a bad name).

 

Cheers,

 

Ryan Jones

[RyanJ]

I have another question, whats the most commonly used oxidant in fireworks?

 

Cheers,

 

Ryan Jones

[YT2095]

Ewwww, that`s a tough question actualy!

 

it REALLY is a toss-up between KNO3 and KClO4, pound for pound and ounce for ounce it`s about even (depending on the manufacturer).

they both get employed for different uses, with some overlapp where either can replace the other.

 

personaly, I wouldn`t like to Guess, but if I had to, it would be the Perchlorates.

[RyanJ]

Ewwww' date=' that`s a tough question actualy!

 

it REALLY is a toss-up between KNO3 and KClO4, pound for pound and ounce for ounce it`s about even (depending on the manufacturer).

they both get employed for different uses, with some overlapp where either can replace the other.

 

personaly, I wouldn`t like to Guess, but if I had to, it would be the Perchlorates.[/quote']

 

So I'm guessing they are the most cost effective and probably have the best results in a majority of cases then?

 

Are there any rare materials used in fireworks like uncommon oxidants tand things?

 

Cheers,

 

Ryan Jones

[YT2095]

there used to be yeah, but not so much nowadays, everything now is as cheap and same(ish) as possible

[RyanJ]

there used to be yeah, but not so much nowadays, everything now is as cheap and same(ish) as possible

 

Well, thats peopel for you only interested in the money, I'd rather see some exotic chemicals burn myself

 

Next question for you explosives exeprts:

 

Whats the most powerful explosive known? I've heared Nitroglycerine is damn powerful with a detination devlocity of about 7700m/s

 

Also, I have another question: Does Nitrogen Triioide explode or does it just decompose very rapidly?

 

Cheers,

 

Ryan Jones

[woelen]

Well' date=' thats peopel for you only interested in the money, I'd rather see some exotic chemicals burn myself

 

Next question for you explosives exeprts:

 

Whats the most powerful explosive known? I've heared Nitroglycerine is damn powerful with a detination devlocity of about 7700m/s

 

Also, I have another question: Does Nitrogen Triioide explode or does it just decompose very rapidly?

 

Cheers,

 

Ryan Jones[/quote']

NI3 explodes. Everything, which makes a BANG noise on ignition can be considered explosive.

 

Detonation velocity tells something about the power of an explosion, but it is not the same (sorry that I used this word in a sloppy way several posts back in this thread). A powerful explosive is one, that produces a lot of energy.

 

The most powerful explosive known to mankind probably is a tritium fusion bomb. A few kilos of tritium (I think it is bound as the lithium tritide, LiT) produce as much energy as several megatonnes of TNT, so that indeed is VERY powerful. One gram of this gives an amount of energy comparable to a million liters of gasoline.

 

The tremendous amount of energy is due to fusion of tritium nuclei to heavier elements. The energies, associated with nuclear reactions are in the order of a million to a billion times larger than the energies, associated with chemical reactions. For chemical reactions, E is in the order of tens or a few hundreds kilojoules per mole, for nuclear reactions these energies better can be expressed as Gigajoules or Terajoules per mole.

[RyanJ]

NI3 explodes. Everything' date=' which makes a BANG noise on ignition can be considered explosive.

 

Detonation velocity tells something about the power of an explosion, but it is not the same (sorry that I used this word in a sloppy way several posts back in this thread). A powerful explosive is one, that produces a lot of energy.

 

The most powerful explosive known to mankind probably is a tritium fusion bomb. A few kilos of tritium (I think it is bound as the lithium tritide, LiT) produce as much energy as several megatonnes of TNT, so that indeed is VERY powerful. One gram of this gives an amount of energy comparable to a million liters of gasoline.

 

The tremendous amount of energy is due to fusion of tritium nuclei to heavier elements. The energies, associated with nuclear reactions are in the order of a million to a billion times larger than the energies, associated with chemical reactions. For chemical reactions, E is in the order of tens or a few hundreds kilojoules per mole, for nuclear reactions these energies better can be expressed as Gigajoules or Terajoules per mole.[/quote']

 

Tritium? I've heared of that before, its [ce]H^3[/ce] right?

 

So, we know the most powerful nuclear based explosive how about the most powerful chemical one then?

 

Cheers,

 

Ryan Jones

[woelen]

Tritium indeed is an isotope of hydrogen with two neutrons, written as [math]^3H[/math].

 

The most powerful chemical explosive I do not know. As soon as I mention one, a slightly more powerful one can be mentioned. This is not such a relevant question. Whether the VOD equals 8000 m/s or 8500 m/s or whether 3000 KJ/kilo or 3500 KJ/kilo is released is not that interesting.

 

What counts for explosives is their usefulness and the cost. E.g. TATP is totally useless crap, due to its sensitivity. Other reasons may make an explosive less useful, such as being very hygroscopic, being extremely toxic, having short shelf-life. Cost also is an important factor. Fulminating gold for instance is very expensive.