Steam at 20 bar and 300^◦C is to be continuously expanded to 1 bar. 

a. Compute the final temperature, the entropy generated, the heat required, and the work obtained per kilogram of steam if this expansion is done by passing the steam through an adiabatic expansion valve. Will the final state be a vapor, a liquid, or a vaporliquid mixture? 

b. Compute the final temperature, the entropy generated, the heat required, and the work obtained per kilogram of steam if this expansion is done by passing the steam through a well-designed, adiabatic turbine. Will the final state be a vapor, a liquid, or a vapor-liquid mixture? 

c. Compute the final temperature, the entropy generated, the heat required, and the work obtained per kilogram of steam if this expansion is done by passing the steam through a well-designed, isothermal turbine. Will the final state be a vapor, a liquid, or a vapor-liquid mixture?