A constant volume tank filled with 2 kg of air rejects heat to a heat reservoir at

Question:

A constant volume tank filled with 2 kg of air rejects heat to a heat reservoir at 300 K. During the process the temperature of the air in the tank decreases to the reservoir temperature. Determine the expressions for the entropy changes for the tank and reservoir and the total entropy change or entropy generated of this isolated system. Plot these entropy changes as functions of the initial temperature of the air. Comment on your results. Assume constant specific heats for air at 300 K.