Five kilograms of air at $427\backslash$deg C and $600$ kPa are contained in a piston$$cylinder device. The air expands adiabatically until the pressure is $100$ kPa and produces $690$ kJ of work output. Assume air has constant specific heats evaluated at $300$ K$.$

Determine the entropy change of the air in kJ$/$kg$$K$.$ Use the table containing the ideal gas specific heats of various common gases. $($You must provide an answer before moving on to the next part.$)$

The entropy change of the air is kJ$/$kg$$K$.$