Permanganate solutions

[rthmjohn]

I make mixtures or KClO3/sucrose for use in my small bang firecrackers. I calculated the enthalpy of reaction for KMnO4 + sucrose and found that it releases slightly more heat than the chlorate mixture. When i lit the permanganate firecracker however, it just went up in flames. I assumed that, due to the large particle size of both my granular permanganate and sucrose, the reaction didn't take place fast enough to burst the container. Would it be possible to stir my mixture in a very little amount of solvent so that the mixture is more intimate? Or can the dissolved permanganate oxidize the sugar in solution? Is permanganate and sucrose simply not a good bursting mixture?

[YT2095]

it`s nothing to do with the enthalpy as such, it`s all about Reaction Rate and Gas products.

the KMnO4 leaves more solid products than the KClO3 (whos only solid should be KCl after).

any solvent that you can find to dissolve the 2 and reform it again will result in a reaction.

you`re also messing on fairly dangerous ground here too, those crackers with sugar and KMnO4 have a shelf life, ANY moisture (even from the air) can trigger a reaction that will result in fire, it won`t care where or when it does it either!

[rthmjohn]

I make them the same day i use them, and they are relatively small and are kept in a fire safe case away from flammables.

[pyromaster22]

you shouldnt make kclo3/sugar mixtures because they are very sensitive to friction and heat. The thing you describe about the kmno4 is also true when its used with aluminium powder. the only difference is that it burns very fast in the open (almost self confining). But as yt2095 rightly said, as soon as you put it in a tough container its more like a silver fountain because it doesnt produce enough gas to rupture it.

[akcapr]

Kclo4 is pretty bad stuff, somewhat unpredictable. Once my kclo4 rocket motor blew up next to me.

[YT2095]

Kclo4 is pretty bad stuff, somewhat unpredictable. Once my kclo4 rocket motor blew up next to me.

 

are you sure you mean the O4 and not the O3?

O4`s very stable, infact it`s the prefered oxidiser in many pyro compostions because of it`s stability as is KNO3.

I think it`s the rocket design itself that was "Unstable"

[pyromaster22]

i have never heard of a potassium perchlorate based rocket comp. if you mean H3 then its chlorate/charcoal. anyway perchlorate is a lot more stable than chlorate.

and yes h3 has a hell of a lot of power.

oh and you must also be mighty rich to be using KClO4 based rocket fuel

[YT2095]

i have never heard of a perchlorate based rocket comp.

 

Now you`ve REALLY surprised me there! seriously, as Ammonium Perchlorate and alu powder with a rubberised binder is standard rocket kit for the more serious enthusiasts.

[pyromaster22]

my bad i meant ive never heard of a potassium perchlorate based rocket comp

anyway candy rocket fuel is often used for large motors also and thats not ammonium perchlorate based, although it has a low specific impulse.

[YT2095]

again KCLO4 and alu (not sure what the binder is though) is common amongst `D` `DD` engines and `E` engines, I`ve not seen any of that comp past there though, although it`s quite possible abroad, but wouldn`t be legal in the UK for "home use"

maybe for Public Display use though, I don`t know?

[pyromaster22]

kclo4 and al...thought that might burn a bit fast and way too hot. the nozzle would surely not hold up to that temperature. and KClO4 is expensive and hard to get. i think gunpowder would surely be a better choice.

Anyway i never knew that KClO4 based comps existed...interesting rocket propellant but not very realistic for anyone in the uk...that might explain why i dont know anything about it.

 

do you mean D as in estes, because they use a gunpowder variant propellant

 

wouldnt be legal?. i dont think any propellant is legal for "home use" if you havent got any sort of license. i think they only let you make 50g of gunpowder for "experimentation" thats not enough for a decent sized rocket!.

[YT2095]

LOL, I knew this "Merge posts" thing would come in handy someday

 

no KCLO4 engines don`t burn much hotter than any other types.

no I don`t mean the Estes types of D engines, the `D` is the grain size, nothing else

 

by "home use" I don`t mean making your own, I mean what you can buy off the shelf for Bonfire night in way of Fireworks and by public Display use I mean proper pyro-engineers contracted by a local council to put on a display. they use things that you can`t buy in the shops

[akcapr]

Ya i meant chlorate sry

[pyromaster22]

dont they use blackpowder in "firework" ropckets? thats what makes them so expensive i suppose. i would have thought that a propellant which contains a metal would burn very hot.

(lol. about those posts i posted one post 3 times cos ma comp is so slow and i had to make them into 3 different posts so that i wouldnt look like a jackass so i just made up some irrelevant q's lol)

[YT2095]

best bet in a situ like that, is don`t bother, a mod will come along (such as myself) see the error and fix it for ya, just leave it and don`t worry

 

yeah most UK fireworks up to about the `D` size are pressed BP based, some at about the `D` size and over are the Perchlorate and alu mix

THOSE engines are the "mutts nuts" if you can get them