Question

Why does free expansion have zero work transfer?

Answer 1

Free Expansion of a Gas. ... We know from the first law for a closed system that the change in internal energy of the gas will be equal to the heat transferred plus the amount of work the gas does, or . Since the gas expands freely (the volume change of the system is zero), we know that no work will be done, so W=0.

Answer 2

Answer:

In free expansion, no external pressure is supplied to the gas. In absence of external pressure, gas expands by its own. Thus, due to zero external pressure and heat transfer, work done is zero.