Carbon reduction to extract metal.?

Question

Everyone know you can extract some metals with carbon reduction from their oxide state. In this reaction, carbon would take the oxygen from the oxide and reduct the metal. But I don't understand why carbon can take the oxygen from the oxide. Why the bond in carbon dioxide is too strong? Also, can I use other elements to replace carbon? Like can I use silicon and form silicon oxide, or can I use some nitrogen compound with weak bond that can be break in low temperture and form nitrogen oxide?

Why carbon is more reactive then most metals?

Answer 1

The clue is indeed the great strength of carbon-oxygen bonds. The carbon-oxygen bond in CO is actually the strongest bond there is, while the carbon-oxygen bonds in CO2 are even stronger than normal C=O double bonds because of delocalisation over the three-atom system.

You can't use silicon because (a) the heat (strictly speaking the free energy) of formation of SiO2 is usually not favourable enough, (b) in cases where it could work, you would be left with your metal embedded in glassy silica, (c) you would have to do all the work to make silicon from silica in the first place.

You can't use nitrogen because the heat of formation of its oxides is generally unfavourable. This is due to the great strength of the bond in the N2 molecule, and explains the fact that nitrogen and oxygen coexist in the atmosphere.

You could in principle use a low stability nitrogen compound, or even ammonia (although the driving force then would be incorporation of the hydrogen into water), but these would be a lot more difficult to come by than carbon, which you can dig out of the ground by the megaton.

Answer 2

Carbon is more reactive than most metals. You can also use other elements from the carbon group. I apologise for not answering all your quesitons, but I don't really understand what you are trying to say.

Answer 3

An Ellingham diagram should help explain part of your answer, you should be able to find one on-line.

CO2 has double bonds because overlap of the p-orbitals can occurr; they are of similar size, in the same period.

SiO4 has single bonds, p-orbitals don't overlap, Si and O are in different periods, therefore different in size.

A simplified answer but it should hold water.

Answer 4

Iron Oxide is purified into Pig Iron

Answer 5

because it is non metal and it has strong octet electron arrangment in it's outermost shell.carbon also has strong van der waals forces of attraction