申論題

12. A rigid box of a volume of 1 m³ contains 1 mole of nitrogen at T = 300 K. The box is connected to a
high-pressure nitrogen gas line at P = 200 kPa and T = 280 K via a valve. The valve is opened and one mole of nitrogen flows into the box. The valve is then closed. The process mentioned above occurs in a very short time, and the temperature of the box increases during this process.
Then heat exchange occurs between the box and the surroundings (which are also at 300 K), and the
temperature of the box returns to 300 K.   Please calculate how much heat is exchanged between the box and the surroundings.  
Note: You can assume nitrogen behaves like an ideal gas with Cp of 29 J/(mole K) under all conditions.