Consider 100 kg of steam initially at 20 bar and 240 degrees C as the system. Determine the change in exergy, in kJ, for each of the following processes:
(a) The system is heated at constant pressure until its volume doubles.
(b) The system expands isothermally until its volume doubles.
Let Tsubzero = 20 degrees C, Psubzer = 1 bar and ignore the effects of motion and gravity.