How come if you light a match in an oxygen enriched confined space the place will blow up? The air ignites but why? What does the oxygen in the air react with? Is it the nitrogen in the air?

I think stuff just burns faster, it doesn't actually explode. I remember a clip of some dudes dumping liquid oxygen on a fire - whoosh!

watching Braniac?

dont believe that shit.

the thing that burns, the match only has a limited amount of energy in it, and that energy isnt enough to create a massive explosion, even if the reaction occured many times faster (though you may hear a pop or a gunshot sound).

theres a few things that might interest you about an explosions concerning fuel-air mixes though.

http://en.wikipedia.org/wiki/Thermobaric_weapon
http://en.wikipedia.org/wiki/Flashover

things just burn ferociously in a pure oxygen enviroment. If you are burning a liquid its just easier possibiltiy for a fuel/air ratio to form, that would permit boom boom. oxygen in air is normally is 19-22%

http://en.wikipedia.org/wiki/Air-fuel_ratio
*not that related, but guy above me covered most bases

in this classic video, you can see that even liquid oxygen wont cause a real explosion (under common conditioners)
http://youtube.com/watch?v=TBLr_XrooLs&feature=related

but if poured in a fine flamable powder, it can be used as a high explosive
http://en.wikipedia.org/wiki/Oxyliquit