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Pronunciation: en'tro-pe

Definition: That fraction of heat (energy) content not available for the performance of work, usually because (in a chemical reaction) it has been used to increase the random motion of the atoms or molecules in the system; thus, entropy is a measure of randomness or disorder. Entropy occurs in the Gibbs free energy (G) equation: ?G = ?H - T?S (?H, change in enthalpy or heat content; T, absolute temperature; ?S, change in entropy; ?G, change in Gibbs free energy).

[G. entropia, a turning toward]

See Also: second law of thermodynamics

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© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review date: Sep 19, 2016.