A piston–cylinder device contains steam at 500 F and 100 psia. The piston is then slowly pushed in so that the steam undergoes a reversible, isothermal process until the pressure reaches 150 psia. Determine 

(a) The increase in entropy (Btu/lb_m · R), 

(b) The heat transfer (Btu/lb_m) from the steam, 

(c) The work transfer (Btu/lb_m) from the piston to the steam. Sketch the process on a T–s diagram and include the vapor dome and isobars at 100 psia and 150 psia.