An ideal gas stream (Stream A), C_P = 5R / 2, 50 mole/h, is heated by a steady-state heat exchanger from 20°C to 100°C by another stream (Stream B) of another ideal gas, C_P = 7R / 2, 45 mole/h, which enters at 180°C. Heat losses from the exchanger are negligible.

(a) For concurrent flow in the heat exchanger, calculate the molar entropy changes (S^out - Sⁱⁿ) for each stream, and Ṡgen for the heat exchanger.

(b) For countercurrent flow in the heat exchanger, calculate the molar entropy changes (S^out - Sⁱⁿ) for each stream, and Ṡgen for the heat exchanger. Comment on the comparison of results from parts (a) and (b).