One mole of CO is initially contained on one-half of a well-insulated, rigid tank. Its temperature is 500 K. The other half of the tank is initially at vacuum. A diaphragm separates the two compartments. Each compartment has a volume of 1 L. Suddenly, the diaphragm ruptures. Use the van der Waals equation for any nonideal behavior. Answer the following questions:

(a) What is cv at the initial state?

(b) Do you expect the temperature to increase, decrease, or remain constant. Justify your answer with molecular arguments. Be specifi c about the nature of the forces involved.

(c) What is the temperature of the fi nal state?

(d) What is the entropy change of the universe for this process?