Thermodynamic study on the sublimation of the three iodobenzoic acids and of 2-fluoro- and 3-fluorobenzoic acids

• Tipo: Artigo em Revista Científica Internacional
• Data: 2000

Autores

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

Revista

Título: Journal of Chemical Thermodynamics

Vol. 32

Páginas: 1727-1735

ISSN: 0021-9614

Editora: Elsevier

Indexação

ISI Web of Knowledge - 25 Citações

Scopus - 24 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia mecânica

Outras Informações

ID Authenticus: P-000-YAG

DOI: 10.1006/jcht.2000.0705

Abstract (EN): The Knudsen mass-loss effusion technique was used to measure the vapour pressures at different temperatures of the following substituted benzoic acids: 2-iodobenzoic acid, between T = 345.20 K and T = 359.17 K, 3-iodobenzoic acid, between T = 347.15 K and T = 363.17 K, 4-iodobenzoic acid, between T = 363.15 K and T = 379.11 K, 2-fluorobenzoic acid, between T = 309.15 K and T = 323.15 K and 3-fluorobenzoic acid between T = 303.17 K and T = 317.16 K. From the temperature dependence of the vapour pressure, the standard molar enthalpies of sublimation were derived by the Clausius-Clapeyron equation and the molar entropies of sublimation at equilibrium pressures were calculated. Using estimated values for the heat capacity differences between the gas and the crystal phases of the studied compounds the standard, p(0) = 10(5) Pa, molar enthalpies, entropies and Gibbs energies of sublimation at T = 298.15 K, were derived: [GRAPHICS] (C) 2000 Academic Press.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9