Thermodynamic study on the sublimation of 3-phenylpropionic acid and of three methoxy-substituted 3-phenylpropionic acids

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

Monte, MJS (Autor) FCUP; Hillesheim, DM (Autor) Outra

Revista

Título: Journal of Chemical Thermodynamics

Vol. 33

Páginas: 837-847

ISSN: 0021-9614

Editora: Elsevier

Indexação

ISI Web of Knowledge - 15 Citações

Scopus - 17 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia mecânica

Outras Informações

ID Authenticus: P-000-TQW

DOI: 10.1006/jcht.2000.0767

Abstract (EN): The Knudsen mass-loss effusion technique was used to measure the vapour pressures at different temperatures of the following compounds: 3-phenylpropionic acid, between T = 305.17 K and T = 315.17 K, 3-(2-methoxyphenyl)propionic acid, between T = 331.16 K and T = 347.16 K; 3-(4-methoxyphenyl)propionic acid, between T = 341.19 K and T = 357.15 K; 3-(3,4-dimethoxyphenyl)propionic acid, between T = 352.18 K and T = 366.16 K. From the temperature dependence of the vapour pressure, the standard molar enthalpies of sublimation Delta (g)(cr)H(m)degrees were derived by the Clausius-Clapeyron equation and the molar entropies of sublimation at equilibrium pressures were calculated. On the basis of estimated values for the heat capacity differences between the gas and the crystal phases of the studied compounds the standard, p degrees = 10(5) Pa, molar enthalpies, entropies and Gibbs energies of sublimation at T = 298.15 K, were derived: [GRAPHICS] (C) 2001 Academic Press.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 11