Does a gas do any work when it expands isothermally if so wh

Does a gas do any work when it expands isothermally? if so, what is the source of the energy needed to do this work? explain

Solution

The change in internal energy of the system in an isothermal process is zero.

Hence, according to first law of thermodynamics

Q-W=0

Q=W

So, all the heat added to the system is used to do work