changing states (liquid to gas) is a physical change, not a chemical change, so its not an endothermaic reation. if you just had LN2 in a sealed container, it wouldnt be cold at all id think. kinda like those electronics dusters. they have a pressurized liquid inside (its not cold), but once you let some out, its expands to a gas and the can gets cold. :shrug:
i dunno, maybe some-1 who knows what they're talking about should shed some light on this LOL!!
