Re: chemistry of an Oxygen fire
LOUIS
Thus 100% oxygen vs 20%; the fuel is stil there in both cases.
******************
And also, a fire comes from:
An exothermic oxydoreduction reaction that the only true thing to say.
The comon idea that "OXYGEN", "HEAT" and fuel must be there all togheter is
wrong because too simplistic and not general.
Of course in 80% of fire incidents, it is true but stil, this doesn't explain
why:
*F2 explodes upon contact with H2 even at -180°C. No heat/oxygen are needed.
*Cl2 is stable with H2 until you increase pressure or introduce sunlight. Idem
---->Thus electronegativity is important.
*Explosive decompositions of C2H2, C2N2, H2N-NH2,NaN3, NCl3, NH3NI3 ...wich
contain no oxygen
---->enthalpy and entropyof formation and of reactions are important.
*The thermite reactions between a reducing metal and a metal oxyde....no oxygen
(O2) and stil a fire!Oxydoredox
2Al + Fe2O3 -heat--> Al2O3 + 2Fe (l) + 3000°C
2Al + 3CuO -heat--> Al2O3 + 3Cu(g) + 4000°C (explosive!!!!)
PH Z
shul...@hotmail.com wrote:
> But what is the fuel in the case of an oxygen fire? Will oxygen ignite if
> it is the only substance present when heat is introduced?
>
> "djbrmiller" <djbrm...@insightbb.com> wrote in message
> news:ikLac.149654$1p.1909829@attbi_s54...
> > Air is about 78% nitrogen, 21% oxygen, and 1% other gases. Nitrogen gas
> is
> > fairly inert and, in the case of fire, only gets in oxygen's way as the
> > oxygen tries to get to the fuel. Pure oxygen gas will cause the fire to
> > burn quicker and hotter. Different fuels have different "flash points",
> > that is, a combination of temperature and vapor density (concentration) at
> > which the fuel can spontaneously ignite. Pure oxygen causes the flash
> point
> > temperature and/or minimum vapor density to decrease, making pure oxygen
> gas
> > a pretty dangerous thing to have around.
> >
> >
Don T
when heat is introduced?" The answer is NO.
If "enough heat" is applied to ordinary atmospheric air some of the
oxygen will combine with Nitrogen. Otherwise it is pretty much as djbrmiller
stated.
--
Don Thompson
"Go tell the Spartans, thou that passeth by here,
That here, obedient to their laws, we lie."
--inscription at Thermopylae
"LOUIS" <Loui...@SKYNET.be> wrote in message
news:40917539...@SKYNET.be...
Dirk Bruere at Neopax
> From the question "Will oxygen ignite if it is the only substance present
> when heat is introduced?" The answer is NO.
Not entirely true.
Oxygen will burn to form heavier elements in the interior of a red giant star.
--
Dirk
The Consensus:-
The political party for the new millenium
http://www.theconsensus.org
Brian Trosko
> Don T wrote:
> > From the question "Will oxygen ignite if it is the only substance present
> > when heat is introduced?" The answer is NO.
> Not entirely true.
> Oxygen will burn to form heavier elements in the interior of a red giant star.
That's a nuclear reaction, not chemical.
LOUIS
PH Z
Dirk Bruere at Neopax
> Nuclear chemistry si a part of chemistry, physic and astrophysic.
>
Yes.
It's part of the Chemistry plan to eventually annex Physics
donald j haarmann
"Dirk Bruere at Neopax" <di...@neopax.com> wrote in message news:c6s47u$fcb99$1...@ID-120108.news.uni-berlin.de...
> LOUIS wrote:
>
> > Nuclear chemistry si a part of chemistry, physic and astrophysic.
> >
>
> Yes.
> It's part of the Chemistry plan to eventually annex Physics
>
> --
> Dirk
------------
Au contraire - The more advanced chemistry becomes .. the more it looks like physics!
donald j haarmann - avvocato del diabolo
LOUIS
Two faces of a single polyedron called science.
PH Z
Roy Basan
If the description becomes more mathematical and less of being
chemical; then it’s on the way of going to the physics side.
It is just like we cannot compare chemical physics to be the same as
physical ehemistry…..
pragmatist
And how many are the angels that can dance
on the point where the two meet?
Pragmatist
"!!I'M SO CONFUSED!!" - Vinny Barbarino 1972