Question

For a process in which the final condition is more orderly than the initial condition, ΔSsys is______ (negative/positive); and entropy change is_________ (unfavorable/favorable) for the process to be spontaneous.

Answer 1

For a process where the final state is more orderly than the initial state, ∆Ssys is negative, and this is typically unfavorable for spontaneity. However, the process can still be spontaneous if the entropy increase of the surroundings compensates for the decrease in system entropy resulting in a positive ∆Stot.

Step-by-step explanation:

For a process in which the final condition is more orderly than the initial condition, ∆Ssys is negative; and entropy change is unfavorable for the process to be spontaneous. The entropy (S) of a system reflects its disorder, and an increase in entropy generally indicates a move towards greater disorder, associated with more microstates. A negative change in system entropy (∆Ssys < 0) means that the system has become more ordered, which is conventionally less likely to occur spontaneously without any external influence. However, for the process to be spontaneous, the overall entropy of the universe, which is the sum of the entropy changes of the system and the surroundings (∆Stot = ∆Ssys + ∆Ssurr), must increase (∆Stot > 0). Thus the entropy change for the surroundings (∆Ssurr) must be positive and larger in magnitude than the decrease in the system's entropy.