Two compartments each of 1m3 capacity are connected by a valve and insulated from the surroundings and from each other. One compartment contains saturated steam at 683.6 kPa and the other contains steam at the same temperature but at a pressure of 101.3 Pa. The valve is opened and the pressure is allowed to equalize. Determine the change in entropy of the system consisting of the two vessels. Is this process irreversible?