Steam is a superheated vapor that is often used for power generation, heating and industrial processes. Steam at 173.6 degrees celcius and with a specific entropy of 6 kJ/ kg-K undergoes a polytropic process with n=1.18 until the pressure becomes 2 MPa; this means the steam is undergoing an adiabatic process where no heat is added or removed from the system during the expansion or compression.

Part (a):
The final temperature of the steam can be determined by using the following equation: T2/T1 = (P2/P1)^((n-1)/n). Using this equation, we can determine that T2 = 159.735°C, which is approximately equal to 160°C as our final temperature after expanding to 2MPa.