A piston/cylinder system containing 1.25 kg of "laughing gas" (nitrous oxide, N20), is initially at 298 K and 1.00 bar. The system then goes through a process where heat transfer adds 101 kJ to the gas, and simultaneously the piston is moved in such a way that the product of pressure and volume in the cylinder is unchanged - in other words pV is constant during the heat addition. After the process has ended, the pressure of the N2O in the cylinder is 0.130 bar. N2O has a molecular weight of 44. (15 points) a) What is the entropy change of the gas due to this process? b) Was this process reversible? (Be sure to justify your answer.) c) Sketch the process on a T-s diagram. (Make sure to clearly label everything)