Expansion Work

[IA_1D]

In discussion section, my TA went over that "a system does no expansion work if it expands into a vacuum", can someone further explain that? I am not sure if I am getting a hang of it.

[Romi Moore 3k]

To my understanding, it means that since there is no resistance to the gas as it expands, no work is done. When gas expands into a vacuum, the reaction occurs so quickly that there is no heat transfer and no work is done.

[Jonathan Sautter 1J]

I believe that in a vacuum, there is nothing for the gas to push against and thus it can't possibly be doing any work if it expands.

[Rachel Fox - 3F]

If there is a vacuum, that means there are no air molecules present in the surroundings. This means that when a gas expands, there are no air molecules that need to be moved out of the way in order for the pressure to be constant, so no expansion work is being done since there are no air molecules to move for the gas to expand.

[Aaron Kwan 3B]

Think of work as helping another molecule, such as by moving it. When expanding in a vacuum, there are no other molecules, so you can't possibly help anything.

[Coraly De Leon]

Hello,
This would be the case because since there is no resistance on the gas as it expands; no external pressure is acting on the gas.