A vessel with a total volume of 0.1 m3 has two compartments separated by a membrane.

Compartment A has a volume of 0.005 m3 and contains 1 mol of ethane. Compartment B has a volume of 0.095 m3 and is evacuated. The vessel sits in an isothermal bath at 100°C. The membrane ruptures, fi lling the entire vessel with ethane. Assuming ethane can be described by van der Waals equation of state, answer the following questions:

(a) What do you expect the sign of ΔU to be? Explain based on your understanding of intermolecular interactions.

(b) Determine the values for ΔU, Q, and W.

(c) Calculate the change in entropy of the system, surroundings, and universe.

(d) If ethane is replaced with n-hexane, do you expect the magnitude of Q to increase, decrease, or stay the same? Explain.