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woelen

Beautiful green fire with barium bromate

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The following is a really nice experiment with a deep green, which I seldom see in fireworks displays.

 

http://woelen.scheikunde.net/science/chem/exps/barium_bromate/index.html

 

You really should see the fire itself. The camera images capture some of the green, but in reality it is much brighter and more saturated. The camera has a difficult job, capturing the beautiful color, due to overexposure (and I cannot adjust its aperture in video-mode :-( ).

 

But anyway, if you have the chems, then you should definitely try this yourself. You can use crude potassium bromate and cheap potteries barium carbonate for making the barium bromate, as described in the thread on making potassium bromate. No need to use nicely refined material.

 

Only the presence of sodium ions should be avoided, those will kill the nice green color.

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Interesting experiment Woelen. Would Carbon work in place of Sulphur in this case (possible making the reaction slower and less vigorous?)

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Unfortunately this will not work. It will burn, but the carbon introduces a strong yellow/orange glow to the mix and the total color will be a much paler green.

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Hmm interesting but it still reacts? How about phosphorus? That would probably be a little violent of a reaction due to the reactivity of phosphorus though. :)

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you wouldn`t get enough mixed with phos before it exploded, Glucose will work though as will potassium (or even barium) Benzoate, they burn neutral enough for Ba ions.

 

Woelen, Great Color! :)

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@YT2095: That doesn't sound like a very wise thing to try (the phosphorus reaction) but the reaction with glucose sounds interesting!

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I have done the phosphorus/bromate reaction (with 20 mg or so) and yes, this explodes. It is not a real detonation, but the burn rate is so high, that even the unconfined powder at 20 mg quantity gives a fairly loud bang. Not useful for making good colors.

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I think I might have a try with the Strontium version of this also, however I`ll Not be able to provide pics, so if anyone else cares to join in.... :)

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How about the lower alkali-earth metal bromates? They'll probably be a little more stable in this case and so easier too observe.

 

If this is correct calcium should also produce a nice red-yellow flame.

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calcium is a nice Pink color, next would be Lithium, after that Strontium, Sr is a Very deep red, K and Ca go well together for sure.

 

but with RP it`s the Anion thats critical (Bromate in this case) and not the Cation so much, in fact bromate and Sulpher should never be stored either!

you make it and then use it, even then it can react without apparent reason, hence mg quantities at a time :)

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What about other bromates? I'm not sure about the reactivity of bromates across the periodic table but something like copper(II) bromate or maybe more exotic bromates?

 

Just a note too anyone reading (probably already know anyway but just to be safe) if you try with strontium bromate be aware that strontium compounds are normally just as toxic as those of barium so be careful :)

 

Sound like there are a lot of possibilities of things to try here, could be interesting to examine the reactivity of iodates maybe too, my guess is though that they may be too unstable to be used in such a situation.

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Iodates aren`t so bad as Chlorates and Bromates.

I`de put them on a par with Nitrates in a flame test, although a drop test may show different results as it Should also be impact sensitive.

Copper would be interesting though, I know it needs normaly a Chlorine doner,it would be interesting to see what another Halogen provides in way of ionisation energy.

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What about other bromates? I'm not sure about the reactivity of bromates across the periodic table but something like copper(II) bromate or maybe more exotic bromates?

For me, the only bromates, which I can make easily are potassium bromate, barium bromate, and with some difficulty, strontium bromate. If I had cesium salts and rubidium salts, then I also could make CsBrO3 and RbCsO3 (and yes, I hope to receive 100 grams of CsBr soon).

The reason why these bromates can be made easily is their large difference in solubility at high temperature and low temperature. This makes separation of the bromates very easy, in fact, the K-, Ba-, Cs- and Rb- bromates are among the easiest to separate chems, due to their unique solubility as function of temperature.

Unfortunately most other bromates are very soluble and there is no easy way to separate them from impurities.

Silver bromate also can easily be made. It is insoluble and forms a precipitate, when e.g. solutions of AgNO3 and KBrO3 are mixed. AgBrO3, however, is more dangerous than the other bromates. A mix of AgBrO3 and Mg powder can be ignited (explosively) by adding a drop of water to the fine mix.

I intend to do some experiments with Ag(NH3)2BrO3 as well, that is a compound, which has oxidizer and reductor in perfect ratio in its own molecule:

 

Ag(NH3)2BrO3 --> AgBr + N2 + 3H2O

 

 

Just a note too anyone reading (probably already know anyway but just to be safe) if you try with strontium bromate be aware that strontium compounds are normally just as toxic as those of barium so be careful :)

Is this true? I always thought that Sr-salts hardly are toxic, provided the anion is not toxic. Of course, Sr(BrO3)2 is quite toxic, but this is because of the bromate, not because of the Sr.

 

Sound like there are a lot of possibilities of things to try here, could be interesting to examine the reactivity of iodates maybe too, my guess is though that they may be too unstable to be used in such a situation.

Iodates are not that interesting in pyro-applications. They are less reactive than nitrates. With sulphur you obtain little more than smouldering, with red P, they give a nice burning mix, something like a coarse mix of KNO3, S and C. KNO3 mixed with red P can lead to flash-like behavior.

Iodates do form an interesting group of compounds in aqueous chemistry. They form amazing precipitates and complexes and also can be used for interesting clock-reactions and oscillating reactions.

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The human body absorbs strontium as if it were calcium. Due to the elements being sufficiently similar chemically, the stable forms of strontium do not pose a significant health threat, but the radioactive 90Sr can lead to various bone disorders and diseases, including bone cancer. The strontium unit is used in measuring radioactivity from absorbed 90Sr.

 

An experimental drug made by combining strontium with ranelic acid has aided in bone growth, boosted bone density and lessened fractures. (El-Hajj, 2004) Women receiving the drug showed a 6.8% increase in bone density. Women receiving a placebo had a 1.3% decrease. (Meunier et. al, 2004). Half the increase in bone density (measured by x-ray densitometry) is attributed to the higher atomic weight of Sr compared with calcium, whereas the other half is assumed to be a true increase in bone mineral content. Strontium ranelate is registered for treatment of osteoporosis in Europe at a dose of 2 grams daily.

 

Several naturally occurring strontium compounds have additionally been found to enhance bone growth and density and lessen the incidence of fractures, and efficacy of treatment has not been shown to vary significantly between various strontium compounds. These compounds include strontium lactate (McCaslin et. al, Mayo Clin. 1959;34(13):329-34), strontium citrate (Wright et. al, Tahoma Clin.), strontium carbonate and strontium gluconate (Skoryna et. al, 1984).

 

 

From Wikipedia, I guess it isn't that bad, except in its radioactive form.

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For me, the only bromates, which I can make easily are potassium bromate, barium bromate, and with some difficulty, strontium bromate. If I had cesium salts and rubidium salts, then I also could make CsBrO3 and RbCsO3 (and yes, I hope to receive 100 grams of CsBr soon).

The reason why these bromates can be made easily is their large difference in solubility at high temperature and low temperature. This makes separation of the bromates very easy, in fact, the K-, Ba-, Cs- and Rb- bromates are among the easiest to separate chems, due to their unique solubility as function of temperature.

Can't you mix barium bromate and a sulfate to get a new bromate and precipitate barium sulfate? For example CuSO4+Ba(BrO3)2->BaSO4+Cu(BrO3)2?

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that should work :)

 

but add then in a liquid dissolved state, and not any one part as a Solid, else it will form an insoluble layer and bork the whole reaction up entirely.

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Iodates are not that interesting in pyro-applications. They are less reactive than nitrates. With sulphur you obtain little more than smouldering, with red P, they give a nice burning mix, something like a coarse mix of KNO3, S and C. KNO3 mixed with red P can lead to flash-like behavior.

Iodates do form an interesting group of compounds in aqueous chemistry. They form amazing precipitates and complexes and also can be used for interesting clock-reactions and oscillating reactions.

 

Really? I would have guessed the opposite due to the general low bond energy of the I-X bond.

 

Ah, I understand Woelen. The solubility factor vs temperature is a problem for most bromates.

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