hummingbird said:
I'm actually assuming there will be half as much Oxygen present as hydrogen ie H20, H2 and O2.
nine tenths of water, is oxygen....Water is eighty-nine percent oxygen by weight
:wink:
atomically speaking
but you are right there will be more free Hydrogen than Oxygen by a factor of 2/3rds but on the subject of oxygen being selective.... it isn't
The view of oxidation and reduction is that of adding oxygen to form an oxide (oxidation) or removing oxygen (reduction). They always occur together. For example, in the burning of hydrogen
2H2 + O2 -> 2H2O
the hydrogen is oxidized and the oxygen is reduced. The combination of nitrogen and oxygen which occurs at high temperatures follows the same pattern.
N2 + O2 -> 2NO
This formation of nitric oxide oxidises the nitrogen and reduces the oxygen. In some reactions, the oxidation is most prominent. For example in the burning of methane,
CH4 + 2O2 -> CO2 + 2H2O
both carbon and hydrogen are oxidized (gain oxygen). The accompanying reduction of oxygen is perhaps easier to see when you describe reduction as the gaining of hydrogen.
On the other hand, the reaction of lead dioxide at high temperatures appears to be just reduction.
2PbO2 -> 2PbO + O2
The reduction of the lead dioxide is clear, but the associated oxidation of oxygen is easier to see when you describe oxidation as the losing of electrons... that's basically how I remember it