A piston-cylinder device contains 0.1 kg of steam at 900 kPa and 320oC. Steam then expands to a final state of 180 kPa and 135oC, doing work. Heat losses from the system to the surroundings are estimated to be 4 kJ during this process. Assuming the surroundings to be at 25oC and 100 kPa, determine (a) the energy of the steam at the initial and final states, (b) the energy change (ΔΦ) of steam, (c) the energy destroyed (I) and (d) the exergetic (second-law) efficiency.