a. Air in closed station systems expands in a reversible adiabatic process from 0.5 MPa, 17 ◦ C to 0.2 MPa. Find the final temperature and also for unit mass of air, calculate the change in enthalpy,...

a. Air in closed station systems expands in a reversible adiabatic process from 0.5 MPa,

17
^◦C to 0.2 MPa. Find the final temperature and also for unit mass of air, calculate

the change in enthalpy, the heat transferred and the work done.

b. 0.2 m³
of hydrogen initially at 2.4 MPa and 200
^◦C undergoes a reversible constant

temperature expansion to 0.2 MPa. Find (i) the work done during the process; (ii) heat

transferred and (iii) entropy change.