A piston-cylinder device contains 0.05 kg of steam at 1 MPa and 300 °C. Steam now expands to a final state of 150 kPa and 160 °C, doing work. Heat losses from the system to the surroundings are estimated to be 2 kJ during this process. Assuming the surroundings to be at T0=25 °C and P0 = 100 kPa, determine: (a) the exergy of the steam at the initial and final states; (b) the exergy change of the steam; (c) the exergy destroyed.