sudden removal spontaneous process 72 new final equil state partition . Initial equil, state Poised for with internal constraint spontaneous process Figure 1: For Problem 3 Fig. 1 shows an isolated system, consisting of a rectangular container made of Adiabatic, Rigid, and Impermeable ("ARI") walls. It has a total length of 2L along 1. The cross-sectional area (not shown) is A. Initially, there is an 'ARI' partition running right down the middle (at 1 = L), creating two compartments. The two compartments have identical volumes, V. . In the initial state, the left compartment is filled with N perfect gas molecules, with an internal energy Eini, and uniform concentration Cini = N/V, at equilibrium. The right compartment is totally empty. The internal partition is an internal constraint on where the gas molecules can be Now, suppose the partition suddenly gives way. That constitutes a release of internal constraint; the molecules are longer restricted to the left compartment. This release initiates a spontaneous process toward a new equilibrium state in accordance with the 2nd Law for isolated systems. (a) Find the final pressure Pfin and temperature Tfin for the gas in the final equilibrium state. (b) Find the expression for the change in entropy, AS = Sfin - Sini. Use the Sakur-Tetrode expression SCE,V,N) = Nky In () + Nkan () () = + (N so) (3) (c) Explain how your expression for AS in part (b.) is consistent with the 2nd Law of 3 Thermo