6. (12 points) Air in a rigid, insulated cubic tank of edge a=60 cm, fitted with a paddle wheel, undergoes a stirring process between two states, namely: State 1: T1

= 40 °C, p1= 4 bar; State 2: T2 =453 °C. (6a). (4p) Please determine the final pressure. (6b). (4p) Please determine the work done in the process. (6c). (4p) Please determine the entropy generated.