Spontaneity and Equilibrium III: A History of Misinformation
| Autor: | Lionel M. Raff |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Journal of Chemical Education. 91:2128-2136 |
| ISSN: | 1938-1328 0021-9584 |
| DOI: | 10.1021/ed500253e |
| Popis: | Necessary and sufficient criteria for reaction spontaneity in a given direction and for spontaneity of finite transformations in single-reaction, closed systems are developed. The criteria are general in that they hold for reactions conducted under either conditions of constant T and p or constant T and V. These results are illustrated using a simple, liquid-to-vapor phase transition as an example. Following this development, the paper investigates the source of the mathematical and logical errors contained in textbooks ca. 1950 to the present that led to the fallacious statements still present in most introductory chemistry textbooks and some more advanced texts that the conditions for spontaneity are ΔG < 0 at constant T and p and ΔA < 0 at constant T and V, whereas the corresponding conditions for equilibrium are ΔG = 0 or ΔA = 0. This investigation shows the principal errors to be (i) incorrect evaluation of definite integrals; (ii) failure to determine whether the results of such integrations produce... |
| Databáze: | OpenAIRE |
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