A piston/cylinder device contains 1. 5 kg of air at 100 kPa and 80 C. The air is compressed in an isothermal process and the work done is 15 kJ. What is the entropy change of the air?
a. 0. 043 kJ/K
b. 1. 07 kJ/K
c. 0. 238 kJ/K
d. 1. 35 kJ/K