so, i've taught chemistry and physics for 15 years, and yet i still need help with this. the classic egg in a bottle demo i'm referring to is the one done with a lit object being placed in the bottle. i get that all those demos calling for heated water that is cooled or using liquid nitrogen to cool the bottle are examples of gay-lussac's law. however, i've seen (on NSTA's website among many many others) teachers stating that the burning a thing method is also an application of gay-lussac's law. this does not make sense to me.
first of all, dropping a burning object into the bottle then immediately capping the bottle with the egg means that the egg has just created a closed system. if gay-lussac's law applied according to the reasoning i've read online, then the heated air should actually increase in pressure and push the egg out, not suck the egg in. secondly, the burning thing (a match, a piece of paper) doesn't burn long enough to significantly change the temperature in the bottle, does it?
thirdly, since the egg closes the system, the only thing that could cause the egg to be sucked into the bottle under these circumstances would be the loss of the pressure that was due to the oxygen being consumed, right? so, then, i have another question: what about the co2 that is produced as a result of the combustion reaction? if burning wood based products is sort of similar to the combustion of glucose, the mole ratio of o2 to co2 should be one to one. since co2 is so much denser than air, is it that it sinks to the bottom of the container and is unavailable for collisions at the top of the container? it seems like a read an article on this many years ago, but i cannot find it now. thoughts?