Re: How would burning be different if the air was pure oxygen?

"Burning" typically describes a chemical reaction called oxidation.  When
burning something like wood, a simple model of the chemical reaction is :
    C12H22O11 + 12O2 --> 12CO2 + 11H20
Complete conversion to carbon dioxide and water represents a total burn in
this example.  More oxygen makes the reaction proceed at a faster rate and
more completely.  However, there are competing reactions.  For example,
carbon monoxide (CO) or formaldehyde might form instead of carbon dioxide
(CO2), or the wood might react with nitrogen oxides and produce urban smog.
 Increasing oxygen will help prevent this.  So, if the air was pure oxygen,
there would be less smog, carbon monoxide, and other by-products formed
directly from the burn.  However, in a pure oxygen atmosphere, it would be
near impossible to actually put out a forest fire, or any ordinary fire for
that matter, because the reaction would proceed too readily. It would be a
give and take.  "Burning" is actually a really complicated reaction
involving radicals and reverse reactions, and I've simplified a lot here,
but I hope this clears things up anyway.