Thermodynamics of thallium alkanoates III. Heat capacity and thermodynamic functions of thallium(I) n-tetradecanoate from 7 to 450 K
The heat capacity of thallium(I) n-tetradecanoate was measured by adiabatic calorimetry to 350 K and by d.s.c. from 235 through 460 K. Good agreement between the methods was obtained within the common temperature range. Several phases were observed in the sample. Two solid-to-solid transitions were...
| Autores: | , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 1987 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/2564 |
| Acesso em linha: | http://www.sciencedirect.com/science/article/B6WHM-4CRHDT1-1F8/2/d4b4843c0ccf2cf688ed08407cab9245 http://hdl.handle.net/10261/2564 |
| Access Level: | acceso abierto |
| Palavra-chave: | Chemical Thermodynamics Thalium alkanoates Thermophysics Heat capacity |
| Resumo: | The heat capacity of thallium(I) n-tetradecanoate was measured by adiabatic calorimetry to 350 K and by d.s.c. from 235 through 460 K. Good agreement between the methods was obtained within the common temperature range. Several phases were observed in the sample. Two solid-to-solid transitions were found, a very sharp one at 318.5 K (Cp, m/R for the maximum is about 104; enthalpy (ΔtrsHm/R) increments are 1913.5 K and 6.00, respectively) and the other at 378.0 K: [ΔtrsHm/R = 346 K, ΔtrsSm/R = 0.92. Between these transitions there is a broad diffuse hump whose maximum is at about 360 K. The sample melts into a liquid-crystal phase at 396.3 K: ΔtrsHm/R = 754 K, ΔtrsSm/R = 1.9. Finally, "clearing" occurs at 460.7 K: ΔtrsHm/R = 201 K, ΔtrsSm/R = 0.44. Smoothed thermophysical properties are tabulated through "clearing". |
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