Question

For all cycles in this section, assume that you have exactly 1.000 moles of gas and that the cycle is run reversibly. The known state parameters for the cycle will be given as the reduced temperature T_r ≡ T /T_c and reduced pressure P_r ≡ P/P_c, where T_c and P_c are the critical temperature and pressure of your assigned diatomic molecule, N₂. Assume the gas is a diatomic van der Waals gas.

You have an Ericsson cycle that begins with an isothermal expansion from an initial state of T_r = 1.75 and P_r = 2.00 to a pressure of P_r = 1.75. The system then undergoes isobaric expansion to a temperature of T_r = 2.00, followed by isothermal compression and then isobaric compression back to the initial state. Calculate w, q, ∆U, ∆S, ∆Ssur, ∆H, ∆A and ∆G for each step in the cycle and for the total cycle.

(entropy S, enthalpy H, Gibbs energy G, and Helmholtz energy A)

Answer 1