Vapor Pressures and Phase Diagrams of Two Methyl Esters of Substituted Benzoic Acids

• Tipo: Artigo em Revista Científica Internacional
• Data: 2011

Autores

Ana R R P Almeida (Autor) Outra; Manuel J S Monte (Autor) FCUP

Revista

Título: Journal of Chemical & Engineering Data

Vol. 56

Páginas: 4862-4867

ISSN: 0021-9568

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 21 Citações

Scopus - 21 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia química

Outras Informações

ID Authenticus: P-002-J86

DOI: 10.1021/je2007605

Abstract (EN): The vapor pressures of condensed phases of methyl p-methylbenzoate and methyl p-(dimethylamino)benzoate were measured in the temperature ranges (269.3 to 357.0) K and (325.0 to 390.4) K, respectively, using a static method. The Knudsen mass-loss effusion technique was also used to study the vapor pressures as function of temperature of the crystals of methyl p-(dimethylamino)benzoate in the pressure range (0.1 to 1) Pa. The results obtained for each compound enabled the determination of the standard molar entropies and enthalpies of sublimation and of vaporization at T = 298.15 K as well as phase diagram representations of the (p,T) experimental data. The temperatures and molar enthalpies of fusion were determined using differential scanning calorimetry and were compared with the values derived from the vapor pressure measurements. The enthalpies of the intermolecular hydrogen bonds O-H center dot center dot center dot O in the crystalline phase of the parent substituted benzoic acids were calculated.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6