Experimental standard molar enthalpies of formation of some 4-alkoxybenzoic acids

• Type: Article in International Scientific Journal
• Date: 2010

Authors

da Silva, MAVR (Author) FCUP; Ana I M C L Lobo Ferreira (Author) FCUP; Maciel, FM (Author) Other

Journal

Title: Journal of Chemical Thermodynamics

Vol. 42

Pages: 220-224

ISSN: 0021-9614

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 2 Citations

Scientific classification

FOS: Engineering and technology > Chemical engineering

CORDIS: Physical sciences > Chemistry > Physical chemistry

Other information

Authenticus ID: P-003-9EG

DOI: 10.1016/j.jct.2009.08.007

Abstract (EN): The present work is part of a research program on the energetics of the linear 4-n-alkoxybenzoic acids, aiming the study of the enthalpic effect of the introduction of an alkoxy chain in the position 4- of the benzoic acid ring. In this work, we present the results of the thermochemical research on 4-n-alkoxybenzoic acids with the alkoxy chain length n = 2, 4, and 8. The standard (p degrees = 0.1 MPa) molar enthalpy of formation of crystalline 4-ethoxybenzoic acid, 4-butoxybenzoic acid, and 4-(octyloxy)benzoic acid was measured, at T = 298.15 K, by static-bomb calorimetry. These values, combined with the values of standard molar enthalpies of sublimation, were used to derive the standard molar enthalpies of formation in the gaseous phase. [GRAPHICS] From those experimental values, the standard molar enthalpies of formation, in the gaseous phase, at T = 298.15 K, are interpreted in terms of structural contributions to the energetics of the substituted benzoic acids and compared with the same parameters estimated from the Benson's Group Method.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5