35 replies to this topic

[Arthur Brown]

A flame is a high energy reaction space. Practically anything can be made some things are ephemeral some things are stable products. Sometimes the mix is made under oxidised for special purposes, Sometimes it relies on atmospheric oxygen to complete the combustion.

[digger]

I agree with AB, this is a very unlikely outcome for this high energy equation

[Mumbles]

The balanced formula is still remarkably close to 75:15:10 actually.  There are more than 30 products formed from burning BP though.

[Crazy Cat]

At Arthur Brown and Digger,

The complete combustion formula without external O2 is, 2 KNO3 + 3 C + S = 3 CO2 + K2S + N2 for BP, and is correct according to;

The Initiation, Burning and Thermal Decomposition of Gunpowder J. D. Blackwood and F. P. Bowden Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences. Vol. 213, No. 1114 (Jul. 8, 1952), pp. 285-306. http://www.jstor.org...=21104138385267 Article image http://www.jstor.org...=21104138385267

Balanced equation formula are:

(1) 2 KNO3 + 3 C + S = 3 CO2 + K2S + N2

and

(2) 10 KNO3 + 3 S + 8 C → 2 K2CO3 + 3 K2SO4 + 6 CO2 + 5 N2

The burning of gunpowder does not take place as a single reaction, however, and the byproducts are not easily predicted. One study's results showed that it produced (in order of descending quantities): 55.91% solid products: potassium carbonate, potassium sulfate, potassium sulfide, sulfur, potassium nitrate, potassium thiocyanate, carbon, ammonium carbonate. 42.98% gaseous products: carbon dioxide, nitrogen, carbon monoxide, hydrogen sulfide, hydrogen, methane, 1.11% water. http://pfrc.students...ki/Black_Powder

 
Other references sources.

http://www.vk2zay.net/composition/1
http://www.vk2zay.net/composition/2
http://www.vk2zay.net/composition/22

http://www.allreacti...um-nitrate-kno3
http://people.ischoo...harles_Wang.pdf
http://www.uroc.org/...n/CHAPTER_1.pdf
http://www.pyrounive...vs-Black-Powder
http://www.ectonhill...lack_Powder.pdf

[Arthur Brown]

It's possible to balance a theoretical equation, but it may not represent the full story. Potassium thiocyanate is a well proven component of burning BP. In fact the mix of combustion products changes with the pressure of the combustion flame.

 

In a gas phase reaction it's a fair guess that every possible product will exist radicals, atoms, molecules and ions, BUT that some will last longer than others, and that every possible equilibrium is happening and is modified by changing temperature and pressure.

 

Davis and Urbanskii both offer good references to the products of BP combustion.

[digger]

At Arthur Brown and Digger,

The complete combustion formula without external O2 is, 2 KNO3 + 3 C + S = 3 CO2 + K2S + N2 for BP, and is correct according to;

The Initiation, Burning and Thermal Decomposition of Gunpowder J. D. Blackwood and F. P. Bowden Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences. Vol. 213, No. 1114 (Jul. 8, 1952), pp. 285-306. http://www.jstor.org...=21104138385267 Article image http://www.jstor.org...=21104138385267

Balanced equation formula are:

(1) 2 KNO3 + 3 C + S = 3 CO2 + K2S + N2

and

(2) 10 KNO3 + 3 S + 8 C → 2 K2CO3 + 3 K2SO4 + 6 CO2 + 5 N2

The burning of gunpowder does not take place as a single reaction, however, and the byproducts are not easily predicted. One study's results showed that it produced (in order of descending quantities): 55.91% solid products: potassium carbonate, potassium sulfate, potassium sulfide, sulfur, potassium nitrate, potassium thiocyanate, carbon, ammonium carbonate. 42.98% gaseous products: carbon dioxide, nitrogen, carbon monoxide, hydrogen sulfide, hydrogen, methane, 1.11% water. http://pfrc.students...ki/Black_Powder

 
Other references sources.

http://www.vk2zay.net/composition/1
http://www.vk2zay.net/composition/2
http://www.vk2zay.net/composition/22

http://www.allreacti...um-nitrate-kno3
http://people.ischoo...harles_Wang.pdf
http://www.uroc.org/...n/CHAPTER_1.pdf
http://www.pyrounive...vs-Black-Powder
http://www.ectonhill...lack_Powder.pdf

 

Exactly my point, you have disproved your orininal post quite comprehensively

[Crazy Cat]

Crazy Cat.
Just a thought you’re not Ushie Mayna are you?

I can assure you I'm NOT!

[Crazy Cat]

Exactly my point, you have disproved your original post quite comprehensively

I agree with AB, this is a very unlikely outcome for this high energy equation

It proves the general formula, the stoichiometry of, 2 KNO3 + 3 C + S => 3 CO2 + K2S + N2 is accepted, and the stoichiometry of combustion products varies as Arthur stated in post #21.

Just as this general formula, stoichiometry, 10 KNO3 + 3 S + 8 C → 2 K2CO3 + 3 K2SO4 + 6 CO2 + 5 N2 is accepted, and the stoichiometry of combustion products varies as Arthur stated in post #21.

Edited by Crazy Cat, 12 June 2014 - 03:58 AM.

[Crazy Cat]

Davis and Urbanskii both offer good references to the products of BP combustion.

A Google search for "Davis and Urbanskii" https://www.google.c...arch&gws_rd=ssl resulted in The Anarchist's Cookbook? Is this it?

[digger]

It proves the general formula, the stoichiometry of, 2 KNO3 + 3 C + S => 3 CO2 + K2S + N2 is accepted, and the stoichiometry of combustion products varies as Arthur stated in post #21.

 

What a load of balderdash. Because someone says something or it happens to balance does not mean that it is proved and correct or even the whole picture. What you need is evidence.

 

The equation stated may be one of the intermediate reactions along the way. It however definitely does not describe the reaction in burning gunpowder and is naive to think so. 

 

The paper which you quote does not say that this is an overall reaction. It simply states that this was used for the manufacture of a sample used for the investigation of initiation and propagation of burning within a sample. In essence the left hand side of the equation was used and not the right (which is clearly not the complete picture).

 

I think you have taken this source out of context I am afraid and quoted it as the DeFacto "this is what happens when gunpowder burns".

 

Furthermore this composition does not represent modern gunpowder. If you do the maths on the formula you will find it is 74.8:13.3:11.8 which is close, but no cigar.

 

If you tried to do the thermodynamics of the reaction stated given the heats of formation then it would be unlikely to give a correct result. Maybe you should do it and find out. I will happily check your maths.

 

To properly do the stoichiometry you need to know what that actual reaction products are rather than just making up a few that happen to fit. So I suggest that you look at the actual reaction products (you have quoted some sources that will help you) and then redo the stoichiometry correctly if you are up to it.

 

What you will find is that it is a series of equations that you need to solve.

 

Good luck

[digger]

P.S. to help get you started Charcoal is not considered to be C, but C7H4O

[Arthur Brown]

Davis - The Chemistry of Powder and Explosives by Tenney L Davis (About 1942)

 

Urbanski  -Tadeusz Urbanski Chemistry and Technology of Explosives Vol 1 to 4

 

Both highly respected texts of some age, not to be confused with assorted cookbooks. Both have learned sections on the reactions of BP and the variability of the products with temperature and pressure.

[Mumbles]

I think this quote from Davis sums things up nicely.

 

"The products of the burning of black powder have been studied by a number of investigators, particularly by Noble and Abel, who showed that the burning does not correspond to any simple chemical reaction between stoichiometrical proportions of the ingredients."

 

If you look at the analysis of the burning mixture in Davis, something sort of interesting is noticed.  Of the solid products (55.91% of all combustion products), 8.74% is sulfur.  This means approximately 50% of the sulfur in the formula is ultimately unutilized. 

 

If anyone in charge here would like to check, I'd be happy to provide my collection of known IP addresses used by Anyka, Ushie, etc. 

Edited by Mumbles, 13 June 2014 - 02:27 AM.

[Crazy Cat]

Just a thought! You obviously know the said individual.

No, I don't know the said individual "Ushie Mayna" whatsoever.

[Crazy Cat]

I'll respond to the combustion of black powder, in finite detail as time permits, with all stoichiometrical formula, thermodynamics, and more.

Hopefully, this debate does not turn into further insults as already stated by Digger, "and is naive to think so."