Final answer:
To visualize the process of steam cooling in a piston-cylinder until half condenses, a T-V diagram would show a vertical drop in temperature while keeping pressure constant, followed by a phase change at constant temperature. The final temperature corresponds to the saturation temperature at 0.5 MPa. Volume change is found using specific volumes from steam tables.
Step-by-step explanation:
Understanding the Piston-Cylinder Device with Steam
When dealing with a piston-cylinder device containing steam that is cooled at constant pressure until half of the mass condenses, several thermodynamic principles come into play.
To illustrate the process on a T-V diagram, one would mark the initial state at the given temperature and pressure, plotting it within the steam region. As the steam is cooled, the temperature would decrease along a line of constant pressure until reaching the saturation temperature correspondent to that pressure. At this point, a phase change would occur, and the diagram would show a horizontal line to represent the constant temperature during the phase change until half of the steam mass has condensed.
The final temperature of the steam after half of it has condensed would be the saturation temperature corresponding to the given 0.5 MPa pressure. Steam tables or a thermodynamic software can provide this value.
The volume change can be calculated by using steam tables to find the specific volumes of steam and water at the given pressure and then finding the difference between the initial and final volumes. The final volume would be an average of the specific volumes of steam and water because half the mass is in each phase.