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The heat capacities of Calorimetry Conference copper and of muscovite KAl2(AlSi3)O10 (OH)2, pyrophyllite Al2Si4O10(OH)2, and illite K3(Al7Mg)(Si14Al2)O40(OH)8 between 15 and 375 K and their standard entropies at 298.15 K

Richard A. Robie·Bruce S. Hemingway·William H. Wilson
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Abstract

The heat capacities of Calorimetry Conference copper and of muscovite, pyrophyllite, and illite were measured between 15 and 375 K using an adiabatic calorimeter. Tables of the thermodynamic functions C° p .( H° T — H° O ) /T , ( G° T —H° O ) /T , and S° T —S° O are presented for these phases at integral temperatures from 0 to. 370 K. At 298.15 K (25.0°C), S° T —S° O is 33.12±0.06, 287.7±0.6, 239.4±0.4, and 1,104.2±0.6 J/(mol•K) for copper, muscovite, pyrophyllite, and illite, respectively. The operation of a semiautomatic data-acquisition system for calorimetric measurements at low temperatures is also described, together with a description of a miniature calorimeter having a novel closure seal.

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Richard A. Robie, Bruce S. Hemingway, William H. Wilson. 1976. The heat capacities of Calorimetry Conference copper and of muscovite KAl2(AlSi3)O10 (OH)2, pyrophyllite Al2Si4O10(OH)2, and illite K3(Al7Mg)(Si14Al2)O40(OH)8 between 15 and 375 K and their standard entropies at 298.15 K. https://pubs.usgs.gov/publication/70233426

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