Question 1 A mass of 0.7 kg of air undergoes two reversible processes in a piston-cylinder device as follow: Process 1-2: Polytropic compression (PV1456 =C) from T1 = 42°C and V1 = 0.3 m³ to T2 =...

Extracted text: Question 1 A mass of 0.7 kg of air undergoes two reversible processes in a piston-cylinder device as follow: Process 1-2: Polytropic compression (PV1456 =C) from T1 = 42°C and V1 = 0.3 m³ to T2 = 247°C and V2 = 0.1 m³. Process 2-3: Constant pressure expansion at P2 = P3 until V3 = V1. Plot the processes on the P-v curve and determine for each process: (a) the change in the entropy by using average specific heat. (b) the change in the exergy. (c) the useful work. Take To= 25°C and Po= 100 KPa