I wanted to ask about the following problem:
An ideal monatomic gas is separated into two volumes $V_{1}$ and $V_{2}$ through a diathermic piston, such that each volume containing $N$ atoms and the two sides are at the same temperature $T_{0}$. The entire system is isolated from the outside by means of insulating walls.
The plunger is reversibly externally manipulated until the two gases are in thermodynamic equilibrium with each other.
After the problem has different questions, however, I have not been able to answer the following:
How is called the type of process? Ie is isothermal, adiabatic, etc. Show that $\Delta S_{1}$ = $-\Delta S_{2}$, where $\Delta S_{1}$ and $\Delta S_{2}$ are the changes in entropy of the two gases.