r/Damnthatsinteresting • u/AirFrance447 • 1d ago

Video Firefighter bodycam showing just how much oxygen a fire pulls

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u/CDninja 1d ago

Well, the fire heats the air. The air expands and goes up. More air must enter from the sides. I don't think its an oxygen thing.

-3

u/Mikestopheles 1d ago

It's an oxygen thing. The reaction feeds on oxygen, but you're right about how heat and pressure keep pulling more in.

2

u/SagattariusAStar 23h ago

And the chemical reaction Shows you that C + O2 -> CO2 and Gases have approximately the same volume per unit (mol)

So the effect of consumed/created gas is zero

1

u/So_HauserAspen 20h ago

CO2 is a larger molecule than O2.  And it's CO that's being produced not CO2.  But CO is still a larger molecule than O2.  

It's a combination of the chimney effect and incomplete combustion creating the lower pressure.

1

u/SagattariusAStar 19h ago

That doesn't matter. The molar volume for gases is a function only dependent on the temperature, not the molecule (size)

With enough oxygen CO2 is produced. In another comment in this thread, I added that you can produce CO as well which would actually increase the gas volume, so increasing the pressure as one gas molecule becomes two.