AndersHoveland
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elements that burn in nitrogen?
I read that only a very small number of elements can burn in nitrogen.
all the alkaline earth metals
lithium
titanium (at 800 °C)
I would think Scandinavium would also.
while bare unexposed aluminum does spontaneously react with nitrogen gas, apparently the bulk metal is unable to burn in nitrogen.
the reaction with hydrogen can be exothermic under certain conditions, but I would prefer not to focus on that here.
sodium cannot burn in nitrogen, in fact even molten sodium will not combine with nitrogen gas at any temperature (sodium nitride is
not very stable, decomposing into its elements at only 87 °C )
So have I missed any? Are there any other elements that can burn in pure nitrogen gas?
[Edited on 28-2-2013 by AndersHoveland]
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Adas
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Maybe Plutonium? 
Rest In Pieces!
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AJKOER
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Magnesium nitride. Per Wikipedia (http://en.wikipedia.org/wiki/Magnesium_nitride )
"Magnesium nitride can be produced by heating magnesium metal in a pure nitrogen atmosphere.
3 Mg + N2 → Mg3N2
In fact, when magnesium is burned in air, some magnesium nitride is formed in addition to the principal product, magnesium oxide."
[EDIT] But wait, per Wiki again:
"The alkaline earth metals are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra)."
so you did cover this one. However, there is Sulfur nitride which may refer to a number of sulfur nitrogen compounds: tetrasulfur tetranitride, S4N4,
disulfur dinitride, S2N2, polythiazyl, (SN)x
[Edited on 28-2-2013 by AJKOER]
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AndersHoveland
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Yes, it appears that cerium can burn in nitrogen also.
| Quote: | Cerium nitride, CeN, is easily prepared by passing perfectly pure nitrogen over red hot cerium (at 850 °C), when the cerium burns in the nitrogen
with a brilliant, white light. The nitride is lustrous and brass yellow to bronze in colour, and is stable in dry air, but in moist air is converted
into cerium dioxide with evolution of ammonia ; when moistened with a few drops of water, a violent reaction sets in, the substance being heated to
redness...
Lanthanium nitride, LaN, is formed by absorption of the gas by the metal at red heat ; this metal does not burn in nitrogen,
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AJKOER
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OK, some rare Nitrides from Group III: InN, GaN
Perhaps there do form directly with N2.
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AndersHoveland
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I doubt it.
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Wizzard
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I think Titanium does, or at least sublimates when heated.
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neptunium
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fluorine will combine with every element except He, Ne and Ar....so yes N2
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Formatik
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Silicon is another.
| Quote: | Synthesis of silicon nitride by a combustion reaction under high nitrogen pressure. DOI: 10.1111/j.1151-2916.1986.tb04750.x
Fine Si3N4 powders were prepared by the combustion reaction of an Si powder compact under 10 MPa nitrogen pressure. Addition of Si3N4 powder to the
starting Si promoted conversion of the reactants to homogeneous Si3N4 particles. Submicrometer Si3N4 powders with a uniform size distribution around
0.5 μm were obtained from a 1.8Si-0.4 Si3N4 mixture (molar ratio); they were free of residual Si. |
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AndersHoveland
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While fluorine can combine, I do not think the two gases can actually burn together.
Fluorine can be mixed with nitrogen without any reaction.
Also, I highly doubt that silicon can burn in nitrogen at normal pressures/temperature. If it could, one would think solid silicon would be able to
burn in air, which it cannot.
[Edited on 2-3-2013 by AndersHoveland]
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AJKOER
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Aluminium nitride. Per Wiki: "AlN is synthesized by the carbothermal reduction of aluminium oxide or by direct nitridation of aluminium".
Also, see "Feasibility of aluminium nitride formation in aluminum alloy". From the abstract (link: http://www.sciencedirect.com/science/article/pii/09215093940... ,to quote:
"The feasibility of forming aluminum nitride by in situ reactive nitrogen gas injection into molten aluminum alloys has been evaluated both
analytically and experimentally over the temperature range from 700 to 1500°C. It is shown that aluminum nitride can be melt formed in the presence
of Mg and Si, with nitrogen and/or ammonia as the reactive gases at temperature above 1100°C. In this role, magnesium serves as a catalyst. Magnesium
niride is first formed in the vapor phase by the reaction of vaporized magnesium and nitrogen gas, followed by incorporation of magnesium nitride
particles into the molten aluminum. Via an in situ substitution reaction, aluminum nitride forms between magnesium nitride and aluminum. Up to 17 wt.%
aluminum nitride in an aluminum alloy has been formed with an average reinforcement size of 3 μm. The potential for this process permits
economical liquid phase processing of aluminum nitride-aluminum metal matrix composite with nitrogen gas injection for structural, thermal and wear
applications."
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AndersHoveland
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Yes, it seems the only reason aluminum cannot burn in nitrogen is because a protective coating of AlN forms which has a very high melting point.
"Aluminum nitride is one of the few materials that is both a good thermal conductor and a good electrical insulator. It is also a high-temperature
ceramic, that has a low thermal expansion coefficient, and low dielectric constant. It is also stable to molten metals such as aluminum, has good wear
resistance, and good thermal shock resistance." Fibrous aluminum nitride can also be created by pyrolysis of certain aluminum compounds. These fibers
are quite strong.
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Eddygp
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Some lanthanides also burn in nitrogen. I think I heard somewhere that Yb and La react with nitrogen without burning to form their respective
nitrides.
Well, someone has already posted that La does.
there may be bugs in gfind
[ˌɛdidʒiˈpiː] IPA pronunciation for my Username |
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bfesser
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<strong>AndersHoveland</strong> is correct. Argon will form a <a href="http://en.wikipedia.org/wiki/Argon_fluorohydride"
target="_blank">fluorohydride</a> <img src="../scipics/_wiki.png" />, but it's only stable below 17 K, and must be prepared at 8 K
using a caesium iodide catalyst and hydrogen fluoride.
[edit]
I've had <a href="viewthread.php?tid=11946">difficulty with calcium</a> in the past, when attempting to fuse small pellets into a solid
lump, due to it's ready ability to burn with nitrogen in air.<a href="http://en.wikipedia.org/wiki/Calcium_nitride" target="_blank"> | Quote: | Calcium nitride is formed along with the oxide, CaO, when calcium burns in air. It can be produced by direct reaction of the elements:
3 Ca + N<sub>2</sub> → Ca<sub>3</sub>N<sub>2</sub> <img src="../scipics/_wiki.png" />
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</a>
[Edited on 7/9/13 by bfesser]
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12AX7
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Most of the left-hand transition metals (including, by extension, the lanthanides and actinides) form nitrides, often very hard and refractory (high
melting). Elements on the right hand side (for example, B, Al, Ga, In) also form reasonably hard nitrides. The former nitrides may melt or decompose
(at 1atm pressure), while the latter tend to sublimate or decompose. Other elements don't form nitrides, tend to be explosive (don't forget azides),
or they contain covalent bonds (anything familiar to organic chemistry in the N, H, C, O, S, Cl, etc. family).
Tim
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AndersHoveland
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Being able to react with nitrogen is not the same thing as being able to burn in nitrogen. Many elements can be made to combine with
nitrogen, particularly with heating, but most of these elements do not release enough heat to sustain the combustion reaction.
Iron nitride can be decomposed to elemental iron and nitrogen gas above 800°C.
Fe3N2 --> (3)Fe + N2
Ca3N2 does not decompose until around 1600°C, at which point the elemental calcium simultaneously vaporizes out with the nitrogen.
Phosphorous does not burn in nitrogen, but P3N5 is relatively stable and does not ignite in air until 600 °C. There is another thread in this forum
about trying to get phosphorous to react with nitrogen, Reaction between nitrogen and phosphorous?
Some of the metal nitrides are explosives:
| Quote: | Fulminating Silver
Aqueous ammonia (NH4OH) is added to silver nitrate (AgNO3). The result is a light tan precipitate.
(2)NH4OH + (2)AgNO3 --> Ag2O + H2O + (2)NH4NO3
silver oxide is a tan to black solid
Ag2O + (4)NH4OH --> (2)[Ag(NH3)2]OH + (3)H2O
With excess ammonia the silver oxide dissolves forming di-amine silver hydroxide.
The latter discomposes on standing forming silver nitride, Ag3N, (the product also possibly containing some Ag2NH and AgNH2).
Mercury Nitride
Mercury(II) nitride forms a chocolate colored powder, which is slowly decomposed by water. The dry nitride tarnishes in air. Mercury(II) nitride is
very explosive, and must be handled with extreme care. It detonates violently, yielding a white flame with a bluish purple border, when heated. The
salt is so sensitive that it can be detonated by rubbing it with a glass stir rod. It is formed by reacting HgO with NH4OH, initially at 10°C, but
thereafter heating the reaction.
(The reaction between mercury(I) nitrate and aqueous ammonia produces a mixture of a white basic amido salt
Hg2ONH2NO3, along with metallic mercury.) |
[Edited on 23-6-2013 by AndersHoveland]
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AJKOER
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AndersHoveland:
I did some research on 'burning' and a general search returns 'combustion'. Wikipedia on combustion notes (http://en.wikipedia.org/wiki/Combustion ), for example:
"Combustion /kəmˈbʌs.tʃən/ or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant
accompanied by the production of heat and conversion of chemical species. The release of heat can produce light in the form of either glowing or a
flame. "
Also:
"Smoldering is the slow, low-temperature, flameless form of combustion, sustained by the heat evolved when oxygen directly attacks the surface of a
condensed-phase fuel. It is a typically incomplete combustion reaction."
from which I infer that many exothermic oxidation reactions occurring at some temperature evolving heat and perhaps light may meet the definition of
combustion/burning.
In fact, Wikipedia also states:
"Nitrogen may also oxidize when there is an excess of oxygen. The reaction is thermodynamically favored only at high temperatures."
although Wiki does not explicitly state that N2, in effect, 'burns' in air at high temperatures.
So, I suggest your reasonable statement "but most of these elements do not release enough heat to sustain the combustion reaction" could be
technically challenged as a precise definition of combustion may actually require only thermodynamically favorably oxidation at whatever the starting
condition happens to be (including temperature, for example, and for the record, I do not live on Mercury).
[Edited on 23-6-2013 by AJKOER]
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Fluorite
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Mmmmmm Heating vanadium in nitrogen atmosphere!
2V + N₂ → 2VN 700 °C
Vanadium nitride is chemically stable, it is destroyed only by boiling with nitric acid and alkali solutions with the release of ammonia
Heh better than Mg nitride if you want ammonia from air
ru.wikipedia.org/wiki/Нитрид_ванадия
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