What is the composition of fire?

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Guillermo Davies

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What is the composition of fire?
« on: 27/07/2008 16:06:07 »
Guillermo Davies asked the Naked Scientists:

Is fire any kind of matter?  If so, which state of matter is it in, plasma,
gas?

What do you think?

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lyner

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What is the composition of fire?
« Reply #1 on: 27/07/2008 17:47:37 »
Fire is more of a 'process' than a substance, I should say.
The 'matter' in a fire is the fuel and the Oxygen (plus Nitrogen, etc, which play no real part).
The oxidation process is very rapid (and exothermal) which raises the temperature and  provides the activation energy to continue the process.
A plasma consists of a mixture of ions which are separated by virtue of the average thermal energy (i.e. temperature) being greater than the potential energy of attraction between the ions. There may be some flames where this happens but I don't think the temperature is high enough in 'yer average' candle flame.
Aren't the fuels and the oxides covalent compounds so the energy would only be available if they actually combined?
Go on, BC - put me right. I promise not to get abusive!

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Offline thedoc

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What is the composition of fire?
« Reply #2 on: 30/07/2008 10:17:35 »
Listen to the answer to this question on our podcast by clicking here

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Offline Bored chemist

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What is the composition of fire?
« Reply #3 on: 30/07/2008 19:12:48 »
Technically a plasma is any ionised gas (subject to being shouted at by physicists) so a candle flame is a dilute plasma. A decent meter will let you demonstrate that a candle flame conducts electricity. Not many of the molecules get ionised, but some do.

Anyway, describing fire as a process rather than a material sums it up rather well.
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lyner

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What is the composition of fire?
« Reply #4 on: 31/07/2008 17:45:14 »
Why do you hate me so?
You are always putting me right (gnaws knuckles and kicks the cat).


I should have remembered the 'flame probe' for detecting high voltage potentials.
« Last Edit: 31/07/2008 17:47:49 by sophiecentaur »

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Offline Bored chemist

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What is the composition of fire?
« Reply #5 on: 31/07/2008 18:52:36 »
Of course, I love you dearly. But my love of scientific truth tends to win out.
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Offline lightarrow

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What is the composition of fire?
« Reply #6 on: 01/08/2008 13:09:49 »
Why do you hate me so?
You are always putting me right (gnaws knuckles and kicks the cat).


I should have remembered the 'flame probe' for detecting high voltage potentials.
[I'm one of them who don't hate you, since I didn't even mention the fact that the "matter" in the flame is more the reaction products, than the reagents...  [:)]]

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lyner

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What is the composition of fire?
« Reply #7 on: 01/08/2008 14:08:06 »
That's true - particularly around the outside.

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Pramod Kandel

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« Reply #8 on: 31/01/2010 18:46:42 »
Why are you fighting? Someone tell what actually is fire. Does it have mass? Can it be made to occupy fixed shape? Why does it flutter? Why is it pointed at top? If it is a reaction, what are the reactants and products? If it were a process, I believe it shouldn't have been such a physical thing which could be seen. If it is a matter, it should be within three states. And Mr. Plasma, I request you to clear your concept as Mr. Process did.

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Anthony Williams \"Bocetti\"

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« Reply #9 on: 05/03/2010 23:41:25 »
Fire is the physical manifestation of an incorporeal reality or the spirit of Yahweh. That is the reason it can't be defined under matter as the other elements are and there has to be three (3) conditions in order to invoke fire. This is showing that the creator Yahweh is a 3-fold unity being the Father, The Word and Holy Spirit. At no point in time will you get Yahweh without the 3-fold unity just like there can't be fire without those 3 conditions present which are the fuel, oxygen and heat.

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Offline Dr. Junix

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What is the composition of fire?
« Reply #10 on: 29/06/2011 10:01:41 »
Fire is the physical manifestation of an incorporeal reality or the spirit of Yahweh. That is the reason it can't be defined under matter as the other elements are and there has to be three (3) conditions in order to invoke fire. This is showing that the creator Yahweh is a 3-fold unity being the Father, The Word and Holy Spirit. At no point in time will you get Yahweh without the 3-fold unity just like there can't be fire without those 3 conditions present which are the fuel, oxygen and heat.

Amen to that.. So fire proves there is indeed God, and therefore disproves other theories such as the big bang, the evolution and so on.


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Offline CliffordK

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What is the composition of fire?
« Reply #12 on: 29/06/2011 10:40:02 »
Fire is the physical manifestation of an incorporeal reality or the spirit of Yahweh. That is the reason it can't be defined under matter as the other elements are and there has to be three (3) conditions in order to invoke fire. This is showing that the creator Yahweh is a 3-fold unity being the Father, The Word and Holy Spirit. At no point in time will you get Yahweh without the 3-fold unity just like there can't be fire without those 3 conditions present which are the fuel, oxygen and heat.
Amen to that.. So fire proves there is indeed God, and therefore disproves other theories such as the big bang, the evolution and so on.

I am not sure you could conclude that fire proves God.

However, if you think of Traditional Chinese Balance (Medicine?), there are five basic elements:

Fire, Wood, Earth, Water, and Metal.

http://healthy-ojas.com/systems/tcm-five-elements.html

I can't really say much about the theory, but:
Quote
Fire is characterized as draught, heat, flaring, ascendance, movement, etc.

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Offline imatfaal

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What is the composition of fire?
« Reply #13 on: 29/06/2011 11:19:13 »
Let's keep it Science please guys! 
There’s no sense in being precise when you don’t even know what you’re talking about.  John Von Neumann

At the surface, we may appear as intellects, helpful people, friendly staff or protectors of the interwebs. Deep down inside, we're all trolls. CaptainPanic @ sf.n

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Offline Mr. Data

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What is the composition of fire?
« Reply #14 on: 29/06/2011 11:20:22 »
Fire is the physical manifestation of an incorporeal reality or the spirit of Yahweh. That is the reason it can't be defined under matter as the other elements are and there has to be three (3) conditions in order to invoke fire. This is showing that the creator Yahweh is a 3-fold unity being the Father, The Word and Holy Spirit. At no point in time will you get Yahweh without the 3-fold unity just like there can't be fire without those 3 conditions present which are the fuel, oxygen and heat.
Amen to that.. So fire proves there is indeed God, and therefore disproves other theories such as the big bang, the evolution and so on.

I am not sure you could conclude that fire proves God.

However, if you think of Traditional Chinese Balance (Medicine?), there are five basic elements:

Fire, Wood, Earth, Water, and Metal.

http://healthy-ojas.com/systems/tcm-five-elements.html

I can't really say much about the theory, but:
Quote
Fire is characterized as draught, heat, flaring, ascendance, movement, etc.

Yes... the link I gave gives a very accurate description of such myths.

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Offline Mr. Data

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What is the composition of fire?
« Reply #15 on: 29/06/2011 11:21:18 »
Let's keep it Science please guys! 

Fire is just infrared light.

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Offline imatfaal

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What is the composition of fire?
« Reply #16 on: 29/06/2011 12:19:36 »
Let's keep it Science please guys! 

Fire is just infrared light.

No. fire is a process in which combustible materials form a hot gas/weakly ionised plasma
There’s no sense in being precise when you don’t even know what you’re talking about.  John Von Neumann

At the surface, we may appear as intellects, helpful people, friendly staff or protectors of the interwebs. Deep down inside, we're all trolls. CaptainPanic @ sf.n

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Offline Mr. Data

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What is the composition of fire?
« Reply #17 on: 29/06/2011 12:29:47 »
Let's keep it Science please guys! 

Fire is just infrared light.

No. fire is a process in which combustible materials form a hot gas/weakly ionised plasma

what do you think this combustable material emmits? wiki states:

''Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products''

Now ask what infrared light is.

''We experience infrared light every time we feel the heat of the sun on our skin or the warmth of a camp fire.''

http://astro.uchicago.edu/cara/about_cara/defn/irlight.html

I know my data.

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Offline imatfaal

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What is the composition of fire?
« Reply #18 on: 29/06/2011 13:49:35 »
Sorry - it's fairly simple; Fire is not just infrared light. (fire gives off infrared amongst other things). You might want to google convection, conduction and radiation as heat transfer methods.  On the campfire example - this is one of the reasons it is much hotter downwind of a campfire than upwind.
There’s no sense in being precise when you don’t even know what you’re talking about.  John Von Neumann

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Offline Mr. Data

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What is the composition of fire?
« Reply #19 on: 29/06/2011 14:10:39 »
You:

''Sorry - it's fairly simple; Fire is not just infrared light.''

Me: pre:

''fire is just infrared light''

You:

''No. fire is a process in which combustible materials form a hot gas/weakly ionised plasma.''

Make up your mind please.

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Offline CZARCAR

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What is the composition of fire?
« Reply #20 on: 29/06/2011 14:27:14 »
ch4 + o2= co2 + h2o. @ the = sign the flame exists. Is there a difference in the mass on the left side [ch4+o2] of the = sign from the right side [co2+h2o]?  ASSUME THE EQUATION IS PROPERLY BALANCED,sorry.

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Offline Mr. Data

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What is the composition of fire?
« Reply #21 on: 29/06/2011 14:31:47 »
ch4 + o2= co2 + h2o. @ the = sign the flame exists. Is there a difference in the mass on the left side [ch4+o2] of the = sign from the right side [co2+h2o]?  ASSUME THE EQUATION IS PROPERLY BALANCED,sorry.

Yes... combustion. If my chemistry suits me well, ch4 is the greenhouse gas... a temperature effect on objects, o2 is the oxygen. As you will notice, these are not fundamental effects. They are atomic. If you want to know the fundamental effects, you ask what fire is made of, and in it's most simplest terms, it is an infrared light, as I have explained. And proved.

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Offline Mr. Data

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What is the composition of fire?
« Reply #22 on: 29/06/2011 14:34:26 »
In fact, o2 is a molecular construction is it not? We need the fundamental answer, which I have given. Atomic was not even close, and molecular physics is even further from the fundamental answer.

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Offline damocles

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What is the composition of fire?
« Reply #23 on: 29/06/2011 16:39:08 »
The most familiar form of fire -- orange, yellow, or white flame -- is due to orange, yellow, or white hot sooty particles. It is a solid aerosol, and not really a gas or a plasma.

Blue flame is due to emission of light from several types of diatomic molecule that are formed in the combustion reaction in excited states -- things like C2, CN, CH, and OH. It involves high energy and unfamiliar molecules, but usually not ions as such.

The presence of trace quantities of metals which easily form ions often leads to characteristic colours of flame: potassium gives lilac flame, barium or copper give green, lithium, calcium or strontium give red. But the one that usually dominates is sodium, which seems to get everywhere, and produces a slightly orange yellow colour in a flame -- the same colour as sodium street lights.

You can tell the difference between these different types of flame very easily with a simple pocket spectroscope. Solid aerosols will show a continuous spectrum; typical flame diatomics a banded spectrum, and metal ions will produce sharp spectral lines.
1 4 6 4 1
4 4 9 4 4     
a perfect perfect square square
6 9 6 9 6
4 4 9 4 4
1 4 6 4 1

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Offline Mr. Data

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What is the composition of fire?
« Reply #24 on: 29/06/2011 16:47:51 »
The most familiar form of fire -- orange, yellow, or white flame -- is due to orange, yellow, or white hot sooty particles. It is a solid aerosol, and not really a gas or a plasma.

Blue flame is due to emission of light from several types of diatomic molecule that are formed in the combustion reaction in excited states -- things like C2, CN, CH, and OH. It involves high energy and unfamiliar molecules, but usually not ions as such.

The presence of trace quantities of metals which easily form ions often leads to characteristic colours of flame: potassium gives lilac flame, barium or copper give green, lithium, calcium or strontium give red. But the one that usually dominates is sodium, which seems to get everywhere, and produces a slightly orange yellow colour in a flame -- the same colour as sodium street lights.

You can tell the difference between these different types of flame very easily with a simple pocket spectroscope. Solid aerosols will show a continuous spectrum; typical flame diatomics a banded spectrum, and metal ions will produce sharp spectral lines.

Gas... plasma... still an infrared energy... I don't understand if you are either challenging the debate, or giving your penny in?

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Offline damocles

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What is the composition of fire?
« Reply #25 on: 29/06/2011 17:46:11 »
Quote
Gas... plasma... still an infrared energy... I don't understand if you are either challenging the debate, or giving your penny in?

OK. 'Twas originally intended as just putting my penny in. The original subject referred to the "composition" of fire, which would normally be a reference to any material content rather than radiation output.

But I will rise to the challenge.

Much of the radiative output isn't infrared energy, though some of it is. But the fact that (most) flames are visible means that fire typically involves visible as well as infrared light energy output.
1 4 6 4 1
4 4 9 4 4     
a perfect perfect square square
6 9 6 9 6
4 4 9 4 4
1 4 6 4 1

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Offline Mr. Data

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What is the composition of fire?
« Reply #26 on: 29/06/2011 19:30:46 »
It says someone has posted.... I don't see this poster's post?

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Offline Bored chemist

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What is the composition of fire?
« Reply #27 on: 29/06/2011 21:34:20 »
Mr Data,
Could you stop talking bollocks please?
Imatfall is perfectly correct. Fire is a process.
That process happens to give out IR, but I also give out IR- yet I am not a fire.
Your assertion that "Fire is just infrared light." is plainly wrong.
Re.
"If my chemistry suits me well, ch4 is the greenhouse gas"
The greenhouse gas effect is physics not chemistry.

"They are atomic."
While there are generally free atoms in flames, they are a long way from the whole story. In fact a flame composed entirely of atoms is not possible, so they are hardly fundamental to the issue of what a fire is.

you say "you ask what fire is made of, and in it's most simplest terms, it is an infrared light, as I have explained. And proved." when you have proved nothing of the sort.

If you carry on in this way you will probably get banned from the site for trolling.
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Offline Mr. Data

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What is the composition of fire?
« Reply #28 on: 29/06/2011 21:45:34 »
I am not talking bollocks. I admitted fire was a process, but I proclaimed the state of matter was of infrared-type: This is what was questioned, and now I am threatened by another member without all the relevent facts. Well, let us leave it at then. I know when I am not welcome.... (even though I contributed to the physics)!

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Offline Geezer

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What is the composition of fire?
« Reply #29 on: 29/06/2011 21:59:42 »

and now I am threatened by another member


Mr Data,

I don't think Bored Chemist threatened you at all, but he did give you very sound advice.
There ain'ta no sanity clause, and there ain'ta no centrifugal force ćther.

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Offline Dr. Junix

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What is the composition of fire?
« Reply #30 on: 30/06/2011 00:48:09 »
well then how do you explain St. Elmo's Fire? It doesn't have the process of combustion as you say.

Also, I think lightning or electricity can be associated or identified as fire.

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Offline Bored chemist

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What is the composition of fire?
« Reply #31 on: 30/06/2011 07:09:26 »
" I proclaimed the state of matter was of infrared-type"
For a start, that's a lie. You claimed "Fire is just infrared light".
Also it makes no sense since infra red isn't a type of state of matter. That#s talking bollocks again.
And then you said you had been threatened.
Well, by whom?
I don't have the power to ban you.
So your talk of a threat is more bollocks.
Would you please stop it.


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Offline Dr. Junix

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What is the composition of fire?
« Reply #32 on: 30/06/2011 07:36:28 »
i think, fire has no absolute chemical composition just like electricity. to create fire, you do not need to follow some chemical rules like creating water which you can easily say as H2O.

And as for my saying that electricity could be associated or identified as fire is that they both share the same characteristics meaning they both burn, generate heat and generate light! It is probably the only element that is in its purest form.


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Offline imatfaal

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What is the composition of fire?
« Reply #33 on: 30/06/2011 10:41:59 »
well then how do you explain St. Elmo's Fire? It doesn't have the process of combustion as you say.
Also, I think lightning or electricity can be associated or identified as fire.

St Elmo's fire does produce light in a very similar manner to non-sooty flames.  The coronal discharge in an electic field creates a small amount of ionisation of the air around the sharp tip of a grounded conductor.  This very weakly ionised plasma/gas glows with the characteristic spookly blueish white light of st elmos fire - which I must admit that, even when you understand the process, is still disconcerting when you first see it.
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Offline Bored chemist

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What is the composition of fire?
« Reply #34 on: 30/06/2011 20:18:26 »
well then how do you explain St. Elmo's Fire? It doesn't have the process of combustion as you say.

Also, I think lightning or electricity can be associated or identified as fire.
I explain it by pointing out that, just because something has the word "fire" in the name doesn't mean it's really fire.
http://www.youtube.com/watch?v=mjxdmsXzwmQ
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Offline Dr. Junix

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What is the composition of fire?
« Reply #35 on: 07/07/2011 09:20:18 »
nice link Bored Chemist.. but your youtube link doesn't explain in detail how fire works...nice dancing though...

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Offline CZARCAR

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What is the composition of fire?
« Reply #36 on: 07/07/2011 20:48:18 »
ch4 + o2= co2 + h2o. @ the = sign the flame exists. Is there a difference in the mass on the left side [ch4+o2] of the = sign from the right side [co2+h2o]?  ASSUME THE EQUATION IS PROPERLY BALANCED,sorry.

Yes... combustion. If my chemistry suits me well, ch4 is the greenhouse gas... a temperature effect on objects, o2 is the oxygen. As you will notice, these are not fundamental effects. They are atomic. If you want to know the fundamental effects, you ask what fire is made of, and in it's most simplest terms, it is an infrared light, as I have explained. And proved.
So if we weigh the fuel be4 the burn & the gasses after the burn they would be equal & the only definition for the flame would be massless infrared?

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Offline Bored chemist

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What is the composition of fire?
« Reply #37 on: 08/07/2011 06:59:15 »
ch4 + o2= co2 + h2o. @ the = sign the flame exists. Is there a difference in the mass on the left side [ch4+o2] of the = sign from the right side [co2+h2o]?  ASSUME THE EQUATION IS PROPERLY BALANCED,sorry.

Yes... combustion. If my chemistry suits me well, ch4 is the greenhouse gas... a temperature effect on objects, o2 is the oxygen. As you will notice, these are not fundamental effects. They are atomic. If you want to know the fundamental effects, you ask what fire is made of, and in it's most simplest terms, it is an infrared light, as I have explained. And proved.
So if we weigh the fuel be4 the burn & the gasses after the burn they would be equal & the only definition for the flame would be massless infrared?

No, because Mr Data is wrong. His is a silly definition.
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Offline mlarsen77

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What is the composition of fire?
« Reply #38 on: 08/07/2011 07:15:15 »
What is fire made of....?   Fire as you see it (energy in the form of light)? Or, what is comprised resulting in fire?  4 components are required for fire to exist (together)...... heat, fuel, oxygen (air), and a chemical chain reaction. In that order...... It was formerly known as the fire triangle, but fire tetrahedron is the proper term as the fourth element being the chain reaction is what enables, and sustains fire buy maintaining heat which seperates gasses from the fuel source and so on.

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Offline mlarsen77

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What is the composition of fire?
« Reply #39 on: 08/07/2011 07:17:07 »
I do not have a degree......didnt even finish college......but I know fire is not made of light...... Light is a form of energy released by the chemical chain reaction.

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Offline Dr. Junix

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What is the composition of fire?
« Reply #40 on: 11/07/2011 01:17:56 »
What is the composition of fire?

I think we have taken the discussion into the wrong direction. With a simple question as that we do not even need to create an equation. Fire doesn't have a definite chemical composition because anything that is flammable can cause fire. It ain't a process either, it is the effect of the process called burning.

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Offline CZARCAR

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« Reply #41 on: 11/07/2011 01:51:12 »
the atoms may glow as the electrons jump shells but radiance is radiance & it has no mass?

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Offline Dr. Junix

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What is the composition of fire?
« Reply #42 on: 11/07/2011 06:50:58 »
no.. fire has no mass.. same as electricity.. you cannot measure the it's mass..