With the same initial states and final volume, the work done by the system is always less in adiabatic expansion than in isothermal expansion. Explain this.
If a gas expands, its initial pressure must behigher than external pressure. With thermal isolation, all the energy for the gas to expand comesfrom the internal energy of gas. The gas will cool down and the pressure will decrease and eventuallyhinder its ability to expand. Under isothermal conditions, the works comes from a reservoirthat has infinite amount of thermal energy: every time that the gas expands a bit, the reservoirwill restore the energy of the system by transferring heat.