Unformatted text preview: A system can only gain order at the expense of disordering its surroundings to an even greater extent. It is sometimes stated that "life feeds on negative entropy (negentropy)." Measurement of entropy for a reversible process at constant temperature: Δ S = Q/T Equation [5] For any real spontaneous process, the entropy change of the universe is always greater than the ideal (reversible) value. Δ S > Q/T When a system departs from an initial state and then returns to the initial state by any real process, the entropy of the universe must increase, even though the entropy of the system (a state function) does not change. Cannot generally use the second law as a criterion to determine if a process will occur. Can sometimes measure Δ S system , but almost never can measure Δ S universe . Need some other state function to determine which processes will occur spontaneously....
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 Spring '11
 SteveHarvey
 Thermodynamics, Entropy, state function, spontaneous process

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