A piston-cylinder assembly initially contains 0.1 m3 of ethylene gas at 393K and 35 bar pressure. The pressure of the gas in the piston-cylinder assembly is reversibly and isothermally brought to 205 bar. (The terms of this compression process will be used in all the options below).

a) Assuming that ethylene obeys the ideal gas equation, calculate the heat transferred (J/mol) and the work done (J/mol) between the system and its surroundings.

b) Assuming that ethylene obeys the Peng-Robinson equation of state, calculate the internal energy change (J/mol) during the process.