Question 5

Consider two tanks, A and B, connected by a valve (figure in the original paper). Each has a volume of 200 L, and tank A has R-134a at 25 °C, 10% liquid and 90% vapor by volume, while tank B is evacuated. The valve is now opened, and saturated vapor flows from A to B until the pressure in B has reached that in A, at which point the valve is closed. This process occurs slowly such that all temperatures stay at 25 °C throughout the process. How much has the quality changed in tank A during the process?

(The printed paper says R-410a; it is corrected by hand to R-134a.)