Molecules move randomly, entropy in this case very strongly favours an even concentration of them throughout the room.
But moving randomly and independently from one another doesn't completely exclude the remote possibility of them all moving towards the same point. It's not completely impossible, but it would be so damn unlikely that I don't expect it to ever be witnessed in the whole life of the universe.
I would argue that it is impossible due to the diffusion gradient. There isn't enough inherent energy in the system overcome that type of entropy.
Furthermore it would need to retain that state for enough time for you to suffocate.
It is so far off the realm of possibilities.
Molecules move randomly, entropy in this case very strongly favours an even concentration of them throughout the room. But moving randomly and independently from one another doesn't completely exclude the remote possibility of them all moving towards the same point. It's not completely impossible, but it would be so damn unlikely that I don't expect it to ever be witnessed in the whole life of the universe.