Is oxygen flammable?

Discussion in 'Chemistry' started by Magical Realist, May 15, 2014.

  1. Baldeee Valued Senior Member

    An intriguing question, MR, for which many of the early answers in this thread are a study unto themselves in how not to answer the question, and endemic of desires in forums for oneupmanship (of which this post alone is clearly an example

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    To whit:
    You state that you know water is the result and is nonflammable, so Billvon explains that water is the product (aka result) and is not very reactive (i.e. nonflammable).
    He restates that it is nonreactive as if this is an answer as to why it is nonflammable.
    And then asks a question that effectively restates your own question.
    "Q: Why is it not X?"
    "A: Why do you think it should be X?"
    Questioning the question without providing the answer sought.
    Yes, very Socratic, but ultimately pointless if the original question is based on a lack of basic knowledge in the matter.

    Origin - genuinely seems to be an actual answer of merit (although I can't speak to the veracity of it... but it looks good!), so thank you.

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    So Russ restates what you have already stated in the OP: "why... does the nonflammable compound of water result?"
    Very informative.
    Other than equating "result" with "ASH" - this suffers the same issues as Russ' answer.

    So let me add my own meaningless responses:
    Is Oxygen flammable: yes, in situations when it is allowed to burn.
    Why isn't water flammable: because it's wet.

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    And didn't some people in the US find their tap water to be flammable due to fracking?

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    (Before you respond that this is not the water producing flames but the gas coming along the same pipes... I'm being facetious).

    Myself, I've only done a tiny but of chemistry, and it's a question I found interesting.
    I was just disappointed with the quality of some of the answers here.
    Hence this post.
    C'est la vie.
    C'est l'internet.
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  3. Aqueous Id flat Earth skeptic Valued Senior Member

    Great tutorials, Origin. You'd make an excellent teacher.

    That probably went over some folks' heads, but was just like the well-said answer by Read-Only, and the similar replies by exchem, billvon & Origin (you guys are the Board of Directors here as far as I'm concerned).

    So Magical Realist: if you burn wood you get ash, but you know that ash does not burn. So if you think of it that way, as Read-Only suggested, then you would not expect the product of anything that burns to also burn. It was also nicely said because "ash" is a meaningful concept to chemists. That being said (for anyone who fools around with cars) if you think of the way burning gasoline incompletely (as in a poorly tuned engine) there is some chance of getting flames out the tailpipe (my first car for example), then maybe that's what you had in mind. But that wouldn't apply here, especially with Hydrogen since it will burn explosively, that is, very rapidly and very completely, and none will be left to just float around in the water. Oh, maybe that was what you were thinking. Maybe you were wondering why some of it isn't left in the water or something like that. (Like the H in H20, though, as the others explained, it's not exactly "H" anymore!) Actually I'm not sure what you're thinking. Just trying to figure out how you came up with the question. Sometimes folks ask what gives materials their instrinsic properties (why is diamond so hard, why is copper a good electrical conductor, and why are good electrical conductors good thermal conductors, and so on. In fact I think you had a thread sort of like that not too long ago.) Maybe you meant the question like this. It's a good question, and of course the very strong panel of chemists (Trippy too) and physicists/engineers we have here have all hit the nail squarely on the head. Understanding properties of materials is sometimes easy and sometimes hard. You picked a real easy one, but only if you look at it from the point sideshowbob is making above--it's a done deal. Once burned, it can't burn again. Which is what all the other folks are saying. And what Bob is also telling you is that is lost its energy (sunk) and so it can't sink any further once it hits the ocean floor. That's more of a physicist's answer than a chemist's answer but really they're all saying the same thing. It's petered out; a goner; dead as a doornail, kaput, out of steam, discharged and basically just all used up. Once that H is bonded to oxygen, it's nothing like H anymore (not as far as flammability is concerned). It's a different material with new properties, one of which is that it's a great way to extinguish most fires.

    For some reason KiteMan doesn't like that answer, probably because he's fussing over the chemical composition of "potash" or something. I think he missed point that the analogy pertains more to the loss of energy as heat of combustion, lowering the potential of the fuel to burn, in fact "sinking it" all the way to zero as it all gets used up. And like I say, more a physicist's perspective than a chemist's. But of course they're all on the same page. (Being a cabal, you know). The Chairmen of the Board. Packin' heat even.

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  5. Magical Realist Valued Senior Member

    So the basic answer to my question is that the two flammable elements create a non-flammable element because the non-flammable element doesn't burn up in the flammable reaction and is left over as a non-flammable element. That was assumed with my statement that water is a non-flammable compound. What I'd still like to know is what makes water non-flammable in it's chemical structure. Is there something about hydrogen molecules being linked to oxygen molecules as water that makes them non-flammable?

    Nevermind. I re-read origin's post and it appears he answered this already.
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  7. Kittamaru Now nearly 40 pounds lighter. Staff Member

    Not quite - oxygen IS consumed during fire - that is why you can "smother" fire.

    A good example - take a glass cup (a tall one) and a tea-light candle. Light the candle and put the cup, upside down, overtop.

    Within a few minutes, the flame will snuff itself out, because all the oxygen is consumed.

    The reason Water is non-flammable is because of precisely what you said - it's molecular structure. It takes, quite literally, more energy to separate the Hydrogen and Oxygen than you get from burning the hydrogen.
  8. KitemanSA Registered Senior Member

    Ash will burn with more powerful oxidizer. For SOME that can be oxygen, for others that is fluorine.
  9. Kittamaru Now nearly 40 pounds lighter. Staff Member

    Technically speaking... isn't Charcoal a type of ash?
  10. exchemist Valued Senior Member

    Technically speaking, no.
  11. Kittamaru Now nearly 40 pounds lighter. Staff Member

    I thought since Charcoal was the deposited remain of burnt carbon compounds - though looking at how it is produced, they specifically mention that a key component is minimizing the creation of ash by heating combustible material (such as wood) in the absence of oxygen.

  12. exchemist Valued Senior Member

    Exactly. The access to oxygen is minimised, so that the wood is heated enough to drive off volatile species, leaving you with unburnt carbon. Some of the wood gets burnt of course and some of the volatiles that are driven off are combustible too.
  13. Trippy ALEA IACTA EST Staff Member

    Water can be oxidized.

    Water can even act as an oxidant - this is why we don't use water to put out vehicle fires involving magnesium alloy rims.

    Water is not as inert as people seem to think it is.
  14. wellwisher Banned Banned

    All atoms in the periodic table, in their neutral or ground state, are at different potentials relative to each other. Some neutral atoms need to lose one or more electrons, while some neutral atoms need to gain one or more electrons to lower potential, to achieve a community average.

    For example, when we react oxygen and hydrogen, oxygen needs to gain electrons, while hydrogen needs to lose an electron, with both atoms able to reach a community ground state as the molecule water. If we add fluorine to this two atom community, fluorine now needs to gain an electron, to lower its potential, which means the others two members of the community; hydrogen and oxygen, have to give up an electron, so the entire community reaches the new average ground state. If we add magnesium to this new three atom community, Mag needs to lose two electrons, to lower its potential, so now the community needs to accept these electrons by rearranging itself again. Depending on which atoms are in the community, these will define the community ground state and what needs to happen within the community.

    On earth, oxygen and water are main players in the chemical community, since oxygen is the most abundant atom on earth, while 70% of the surface of the earth (useful to humans) is covered by water. Since the other atoms have potential needs, but are fewer in number, the community average is influenced by the atomic abundance of each member of the community. We can make some atoms more concentrated, to increase their percent share in a beaker, but left to its own devices, the global average of the oxygen/water heavy community will shift he reactions over time back to a community average.

    Water can't burn, spontaneously on earth, because it is already defining lowest potential via the global average. But we can set up artificial scenarios where we add more concentrated atoms, than natural averages, to generate a new local community potential where water needs to shift.

    An interesting situation that the earth presents is, the metallic iron core of the earth sets a potential with the surface of the earth, since if we mixed the surface community of atoms, with the atoms of the core iron, the iron would want to give up electrons. But the separation between core and surface of the earth slows this averaging process into two community averages. One would expect net electrons coming from the iron core, going to the surface so the earth, attempting to redefine the community average in a way that better reflects needs of iron atoms.
  15. Russ_Watters Not a Trump supporter... Valued Senior Member

    But neither water nor oxygen can act as a fuel -- which was the OP's question.
  16. wellwisher Banned Banned

    If you look at the reaction of ATP into ADP plus phosphate, this is a reaction that will oxidize water. For the phosphate group to leave ATP, to form ADP, water has to be absorbed. The open end previously shared the oxygen on the leaving phosphate. The water that attaches loses a hydrogen proton in the process, thereby causing the original water to become oxidized due to the new higher ratio of oxygen to hydrogen (and phosphorous +7). The reverse is assisted via hydrogen proton pumps in the mitochondria which help to reduce the water back so it can be part of the continuous phase.

    Water can also act as a fuel, but in a way that is different from conventional fuel. This potential energy is connected to surface tension. When water comes in contact with organic materials and surfaces, such as oil, these don't mix well. A tension that forms between them. The energy/tension problem lies mostly with the water, more than the organic.

    The organic is used to weak binding forces between it and other organic molecules; van der Waals. Water is able to provide van der Waals interaction to the organics. Water, on the other hand, is not as satisfied by the bonding with the organics, since water needs the much stronger hydrogen bonding, with the weak binding of organics, just not enough for the needs of the water. The water stays at higher free energy during the interaction. Life make use of this extra energy due to the high surface contact between water and organics.

    Water flowing in carbon nanotubes has a flow rate much higher than expected. Instead of a continuous flow, the flow of water is intermittent, with rapid bursts of water activity. The surface contact between water and carbon, does not favor the energy needs of the water, causing water to gain energy. The bursts of activity sort of discharges the energy. Nature designed water and organics not to mix, so this extra potential energy can become available for a range of added energy affects useful to life.
  17. wellwisher Banned Banned

    Oxygen is the third most abundant element in the universe behind only hydrogen and helium. The hydrogen and helium of the universe formed during the creation of the universe. The oxygen was created later through nuclear fusion in stars. The abundance of oxygen, within the universe, even though fusion needs to build many other atoms in the middle first; Li, Be, B, C, N, indicates a high level stability built into the nucleus of the oxygen atom. The result of its abundance and its unique nuclear stability, oxygen becomes the ground state atom of the universe.

    For the atoms of life to grow/fuse into larger atoms, from Hydrogen, to Carbon, to Nitrogen, to finally to Oxygen, the fusion reactions result in mass burn via E=MC2. This means that per nucleon in the nucleus, the hydrogen has the most mass (no mass burn yet) while oxygen has the least mass per nucleon (has to undergo 5 mass burns to reach the stable oxygen nucleus).

    The formation of water, which is the most abundant molecule in the universe, combines two separated states of nucleon mass density, resulting in a built in potential at the level of mass. The hydrogen will be at higher mass/energy potential, relative to the oxygen. Within water the hydrogen proton is very active with the pH effect able to break strong covalent bonds with low ambient energy.

    In carbon and hydrogen compounds the potential of carbon is higher than oxygen, due to fewer mass burns. There is a different range of behavior in the hydrogen, since the C and H with less mass potential. These hydrogen tend to stay put and don't leave all that easy. As we combine water with carbon/hydrogen compounds we get phase separation into layers due the segregated energy potential. In carbon nanotubes the hydrogen of water need to gain potential to bind in this restrictive environment. The result are bursts of kinetic energy through inertial effects.
  18. origin Trump is the best argument against a democracy. Valued Senior Member

    The ground state atom does not really mean much. Being the 3rd most abundant atom in the universe does not directly indicate that it has a 'unique nuclear stability'.

    Florine would have 6 'mass burns' so it should be more stable, right?

    The effect of the hydronium ion is not an atomic 'mass/energy potentia'l it is purely electric chemical process.

    This seems like some musing that you are doing and nothing more. If I add a neutron to the nucleus of an atom this will result in a higher 'mass/energy potential' for the nucleons yet this will frequently make the nucleus unstable.
  19. exchemist Valued Senior Member

    Quite so.

    If there is such a thing as a "ground state atom of the universe" (a concept of fairly doubtful meaning), surely the strongest candidate is iron, since Iron has the most stable nucleus of all elements.

    And water is NOT the most abundant molecule in the universe. Unsurprisingly, that accolade goes to diatomic hydrogen:
  20. Trippy ALEA IACTA EST Staff Member

    I wasn't suggesting that it could - at least not by any definition of 'fuel' that I'm aware of (all of which evolve around combustion).

    My point was simply that water wasn't some magical inert 'thing' like many people seem to think it is.

  21. wellwisher Banned Banned

    It is not purely coincidental that oxygen is the most abundant fusion product, even though star size varies and star size impacts fusion rate and the heat output. The universal average reflects unique stably in the oxygen atom. If we burn a small amount of wood, or a large amount of wood, we always get water since this is a stable end product. We can get carbon monoxide or carbon dioxide. There are chemical steps in the middle, that might vary based on how hot the flame is, such as radial intermediates, but overall stability considerations cause all the reaction to drift toward water. The same is true of nuclear combustion via mass burn regardless of the scale of stellar fusion.

    My guess is helium, which is number two in atomic abundance, which formed with hydrogen at the beginning, has two protons and two neutrons and will form a nuclear tetrahedron shape. This configuration maximizes 4-nucleon contact. Other isotopes of helium which change nuclear shape away from the tetrahedron and these will tend to decay. Oxygen 16, is a tetrahedron of tetrahedrons.

    If you believe in the unified theory of force, proposed by Einstein, then all forces are connected at some level. Certain configurations of the nucleons in the nucleus, will define the strongest connections to the orbital electrons, influencing the chemistry of the atom. Cold fusion and cold fission takes advantage of this in reverse fashion. We can impact nuclear stability via tweaking electron orbitals. via unified force field connections.

    Magnetic properties, such as with iron, create a nucleon shift into a slightly higher yet stable nucleon state, that locks the connected electrons. Without the cooperation of the nucleus configuration for stability, the magnetic properties would break down faster.
  22. exchemist Valued Senior Member

    Note to readers: the last 2 paragraphs are the personal views of the writer and bear no relation to commonly accepted science.

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