9 replies to this topic

[XtRaVa]

Hi, I was under the impression that, you can hold a flame to KNO3 and it will burn, I saw a program where they were making fireworks, and one person used bat droppings to form potassium crystals, and when he grinded it, and held it to a flame it burnt vigorously with a pinkish flame. However when I try to burn a small amount of KNO3 in a controlled fire, it doesnt burn at all, in fact, the most ive ever seen it do, is melt. Surely this isnt right, is my KNO3 not working properly?

[Pyromaster2003]

ofcourse KNO3 wont burn vigirously when you try and light it with a lighter. its and oxidizer, and oxidizer needs a fuel to burn vigirously. if you sprinkle some on a fire it should cause the fire to burn vigirously for a short time because the O2 is getting released when it burns on the fire.

[XtRaVa]

I didnt think it should burn, I am now somewhat confused as to the program I saw. I cant remember what its called, but its on BBC2 late night sometimes, and its a group of people on an island that have to make things, actually I think its called something like raw science. Anyway, thanks.

[zanes]

Originally posted by XtRaVa
I didnt think it should burn, I am now somewhat confused as to the program I saw. I cant remember what its called, but its on BBC2 late night sometimes, and its a group of people on an island that have to make things, actually I think its called something like raw science.  Anyway, thanks.

yeahits called rough science. Judging from memory i dount who ever made the fireworks was using scratch built chems

[Stuart]

It was called rough science. They used a similar method in the anarchists crapbook I think.

[XtRaVa]

Thats the one, I remember they were just given sulphur, and then conveniently found bat droppings which formed the most perfect potassium crystals lol

[Stuart]

And they somehow managed to make about 10 kilos for all the fireworks.

[phildunford]

Was pretty skeptical myself.

The chemist in the series (Mike sombody?)
had the worst 'hit rate' of anybody. - He would try and do the thoeretical reactions to get his end product, end up with something very inpure and then magically find some pure product for the end of the programme - suspicious eh???

[leniol]

When we refer to burning, we commonly mean something 'burns' oxidation of a chmical with a release of heat at the same time. As KNO3 is already oxidised, it won't burn- it does however decompose & it giveoff oxygen hich will aid the comustion of any chemicals it's mixed with eg. charcoal & sulphur in bp. KNO3 can be extracted from bat droppings; the majority of that used in the past centuries was extracted from chilean guano (bird/bat dung from.... Chile!) As for flame colour, potassium burns white as do it's associatedcompounds, though the flame will be coloured by whatever you mix it with or any impurities. Try making some BP with your KNO3 & see if that burns- I'm sure it will....

[Stuart]

Here's a little bit of history for you.
I dont know if the law has changed but the monarcy had the right to come into your house and dig up the top soil if that was what you walked on. They would then extract the Potassium Nitrate from it.

[Edited on 25-7-2003 by Stuart]