Use the information below to generate a citation. Then you must include on every digital page view the following attribution: If you are redistributing all or part of this book in a digital format, Then you must include on every physical page the following attribution: If you are redistributing all or part of this book in a print format, Although derived for a mechanically reversible process, this equation relates properties only, and is independent of the process causing the change of state. So if we want to calculate the entropy change S, we can arbitrarily choose some. Want to cite, share, or modify this book? This book uses the Recall that entropy, which is defined as qrev/T, is a property of state. The net change in entropy of the system for the transition is The change in entropy for each step is О” S i = Q i / T i. This can be accomplished experimentally by placing the system in thermal contact with a large number of heat reservoirs of varying temperatures T i T i, as illustrated in Figure 4.15. During each step of the transition, the system exchanges heat О” Q i О” Q i reversibly at a temperature T i. So the total entropy change (of the Universe, ie system + surroundings) brought about by the reaction is +307 J K1 mol-1. The temperatures associated with these states are T A T A and T B, T B, respectively. Imagine a system making a transition from state A to B in small, discrete steps. The change in entropy of a system for an arbitrary, reversible transition for which the temperature is not necessarily constant is defined by modifying О” S = Q / T О” S = Q / T. The same equation could also be used if we changed from a liquid to a gas phase, since the temperature does not change during that process either. He stated that every spontaneous change in nature tends.

О” S = 16.8 kJ 273 K = 61.5 J/K О” S = 16.8 kJ 273 K = 61.5 J/KДuring a phase change, the temperature is constant, allowing us to use Equation 4.8 to solve this problem. Employing statistical mechanics in 1877 Boltzmann suggested a microscopic explanation for entropy.

Change in entropy equation