If Silicon nitride (N4Si3) is heated with Aluminium phosphide(AlP) what would be the likely formula of the mass formed?
And Thanks in advance for any helpAdas - 25-10-2011 at 04:30
If something like N4Si3 exist, it would be likely to explode when heated barley81 - 25-10-2011 at 12:13
Nope - Think again:
"Silicon nitride (i.e. Si3N4) is a hard ceramic having high strength over a broad temperature range, moderate thermal conductivity, low coefficient of
thermal expansion, moderately high elastic modulus, and unusually high fracture toughness for a ceramic." - Wikipedia
Decomp. temp - 1600C
This is just speculation - I think aluminum nitride, silicon, and phosphorus would be formed. Just a guess. (AlN, Si, P<sub>4</sub>AndersHoveland - 25-10-2011 at 16:43
I am usually very good at making these types of speculative predictions, but in this case it is more complicated. Nitrogen is a more electronegetive
element than phosphorous, so from this perspective aluminum nitride is likely to form. On the other hand, nitride is a stronger base than phosphide,
and so aluminum, which is a metallic element, may be more likely to bond to phosphorous, since the bonds could potentially be more polar.
Aluminum can reduce silica (SiO2) because aluminum is a more electropositive element.
Aluminum can also reduce sodium oxide (Na2O) because oxide ions are basic and aluminum ions are somewhat acidic (in terms of the Lewis conception of
acidity of course).
I do not think the bonds between silicon and phosphorous are especially strong, which does not add much support for prospects of a reaction.
Not having actually tried the reaction, I can only give my opinion that there would be no obvious reaction between Si3N4 and AlP. But it is
certainly likely that the two compounds might fuse together into an amorphous mass. Under carefully controlled conditions (unlikely for the amateur
chemist), crystals with definite chemical compositions may even be obtainable. Again, in my opinion, it is probably more favorable for each nitrogen
atom to be bonded to one aluminum atom and two silicon atoms.
[Edited on 26-10-2011 by AndersHoveland]D4RR3N - 26-10-2011 at 08:17
Thanks for the help guys, similar question if SiO2 was heated with AlP what would be the likely result?AndersHoveland - 26-10-2011 at 09:46
In my opinion, a reaction is more likely to occur if SiO2 and AlP are heated together. Aluminum usually has a very high affinity for oxygen, even more
than silicon. In this case, silicon phosphide is likely to form. But again, I am not entirely certain.
One book mentions that when sodium phosphate is energetically reduced using aluminum powder, half the phosphorous vaporizes out in elemental form,
while the other half forms aluminum phosphide. But by smelting with the addition of silica, all the phosphorous is converted to elemental form. (The
Mineral Industry, Volume 7, p557)
I suggest you look at the heats of formation of the proposed reactants and compare them to the proposed products to determine if a reaction is likely.
[Edited on 26-10-2011 by AndersHoveland]D4RR3N - 26-10-2011 at 10:31
That’s what I’m looking for
I’m looking to make a crystal which will contain aluminium oxide + Silicon Phosphide
or
A crystal that contains Aluminium nitride + Silicon Phosphide.
Is there anyway such a crystal could be made at lower temperatures, SiO2 melts at 1600c AndersHoveland - 26-10-2011 at 10:42
I’m looking to make a crystal which will contain aluminium oxide + Silicon Phosphide
If you only want to make silicon phosphide, there are probably much better routes.
You could reduce silica with magnesium powder to make Mg2Si. Then react with dilute hydrochloric acid (in the absence of air) to make silane, SiH4.
The silane could be immediately passed into molten phosphorous. This would all have to be done in an inert atmosphere, because both SiH4 and molten P
spontaneously ignite on exposure to air.
Is there anyway such a crystal could be made at lower temperatures?
Al2O3, AlN, and SiO2 all have very high melting points. You will find it very difficult to get such compounds to react, if there is any reaction.
Sodium oxide could be added as a flux to reduce the melting point of Al2O3 or SiO2, but this is likely to interfere with the desired reaction. So
basically the answer to your question is no.D4RR3N - 26-10-2011 at 12:04
What I mean is that I want to create a crystal/mass which contains both Aluminium nitride and Silicon phosphide or a crystal/mass that contains both
Aluminium oxide and silicon phosphide.
Aluminium hydroxide decomposes around 300C as far as I understand it, If I boiled aluminium hydroxide powder with silicon phosphide powder would I end
up with a mass of aluminium oxide + silicon phosphide? AndersHoveland - 26-10-2011 at 12:13
Aluminium hydroxide decomposes around 300C as far as I understand it, If I boiled aluminium hydroxide powder with silicon phosphide powder would I end
up with a mass of aluminium oxide + silicon phosphide?
I do not think so. Intense heat will almost certainly be required. This may likely not be feasible for the amateur chemist. Perhaps a
thermite mixture of Al powder, aluminum phosphate, and silica?D4RR3N - 26-10-2011 at 13:06
I have a small electric furnace with a max temp of 1100C, also I think aluminium hydroxide would heat in a microwave oven.D4RR3N - 26-10-2011 at 13:40
EDIT> Would silicone phosphate ignited with aluminium powder produce a mass of aluminium oxide plus silicon phosphide?
Was looking for powdered silicone phosphate but cant find any?
[Edited on 27-10-2011 by D4RR3N]D4RR3N - 27-10-2011 at 09:54
Guys I was looking to purchase some Silicone Phosphate however after searching I cannot find one single supplier. Have I the name correct or does it
not exist, just don’t understand why I cant find any!
stygian - 27-10-2011 at 12:50
I dont think I've ever heard of silicon (not silicone) salts other than halogens AndersHoveland - 27-10-2011 at 13:12
Silicon sulfide can be formed by the exchange reaction between SiO2 and Al2S3, so this suggests that the prospects of your proposed reaction are good.
I would think that compounds such as silicon sulfate would certainly be possible, but rather cumbersome to prepare. How exactly would one go about
making such a compound? In any case, these types of compounds would likely easily decompose if heated.D4RR3N - 27-10-2011 at 14:36
Silicon phosphide apparently exists and it is possible to purchase that (see link) however have not seen any info on silicon phosphate.
I’m looking to make a crystal which will contain aluminium oxide + Silicon Phosphide
or
A crystal that contains Aluminium nitride + Silicon Phosphide.
This is oxymoronic. You should rephrase your wish to make sense (A crystal containing the elements Al, O, Si, P? A crystal containing modules of the
structures of Al2O3 and SiP?) I see the possibility of a Al,Si,O mixed oxide, but a modular Al2O3/SiP crystal? Not really.
Quote:
Guys I was looking to purchase some Silicone Phosphate however after searching I cannot find one single supplier
There is a "silicon diphosphate", which has SiO6 octahedra instead of the much more common SiO4 tetrahedra. But like alumiunium phosphate, the name is
a bit of a misnomer - these are mixed oxides NOT (di)phosphate salts.
If you cannot buy it, it's probably trivially made from SiO2 and P2O5
Quote:
I dont think I've ever heard of silicon (not silicone) salts other than halogens
SiCl4 is certainly not a salt. Look at the periodic table - Si is just a fat C. D4RR3N - 28-10-2011 at 06:09
“crystal” is the wrong word, I should have said I want to produce a fused mass of aluminium oxide + silicon phosphide or aluminium nitride +
Silicone phosphide.AndersHoveland - 29-10-2011 at 13:59
Not sure about how to making silicon phosphate. But silicon sulfate might be obtained by reacting silane gas with liquid sulfur trioxide, the silicon
sulfate would separate out as a solid.
