A model of the lungs is made of a balloon, a glass container, and a movable diaphragm. A straw is used to connect the balloon to the atmosphere. The balloons are inflated when the diaphragm is pulled downward and deflated when the diaphragm is released. An ideal PV diagram for the process is shown below. The actual PV diagram has curves, not straight lines. The pressure used is gauge pressure, not absolute pressure. This process differs from other processes in that pressure variations are caused by changes in the quantity of gas rather than changes in temperature. If the model is operated at a temperature of 25°C, determine the greatest number of moles of gas attained in the balloon.