Eventually, all of the water has condensed and the cylinder contains saturated liquid water
at 225oC. Is this process internally reversible? Reversible? Irreversible? Explain your answer.
What can be said about
this case of heat transfer process for (a) isothermal cooling of the water and (b) contact between 225oC and 25oC surroundings?
The system is the water in the piston-and-cylinder assembly.
The system undergoes a constant-temperature process from saturated vapor to saturated liquid.
/ Data / Solve:
are needed to resolve this problem.
There are no equations to solve.
None of the
assumptions made can be verified with the given information.
Since the temperature is constant during the process, the pressure also remains constant. As shown by the
T-V Diagram, the
process is a sequence
of equilibrium states,
and thus is internally reversible.
The process is
not reversible because there is a
significant irreversibility in the surroundings.The spontaneous heat transfer taking
place between the water at 225oC and the surroundings at 25oC is irreversible.