An isolated, perfectly insulating box is divided into two equal compartments by a thin, rigid, removable partition. The left compartment contains 0.050kg of ice at 0∘C; the right compartment contains 0.050kg of steam at 100∘C. The partition is suddenly removed, allowing the two substances to come into thermal contact without exchanging matter with the surroundings.
(a) Without doing numerical calculations, discuss qualitatively the direction of energy transfer that will occur after the partition is removed and identify the final phase or phases of water that will exist after equilibrium is reached.
(b) Rank the entropy of the system in the following three states from lowest to highest: (1) the initial separated state, (2) the instant just after the partition is removed but before any temperature change has occurred, and (3) the final equilibrium state. Justify each step of your ranking.
(c) Explain how the second law of thermodynamics constrains the possible final state you described in part (a).
(d) If, instead, the box were not perfectly insulating and could exchange heat with a reservoir at 25∘C, discuss qualitatively how the entropy change of the reservoir would affect the total entropy change of the universe during the process.