Thermodynamic study of the sublimation of eight 4-n-alkylbenzoic acids

• Type: Article in International Scientific Journal
• Date: 2004

Authors

Monte, MJS (Author) FCUP; Almeida, ARRP (Author) Other; da Silva, MAVR (Author) FCUP

Journal

Title: Journal of Chemical Thermodynamics

Vol. 36

Pages: 385-392

ISSN: 0021-9614

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 39 Citations

Scopus - 38 Citations

Scientific classification

FOS: Engineering and technology > Mechanical engineering

Other information

Authenticus ID: P-000-AJQ

DOI: 10.1016/j.jct.2004.02.001

Abstract (EN): The Knudsen mass-loss effusion technique was used to measure the vapour pressures at different temperatures of the following 4-n-alkylbenzoic acids: 4-methylbenzoic acid, between 319.68 K and 337.33 K, 4-ethylbenzoic acid, between 321.17 K and 335.25 K, 4-propylbenzoic acid, between 331.16 K and 347.16 K, 4-butylbenzoic acid, between 333.16 K and 349.15 K, 4-pentylbenzoic acid, between 341.16 K and 357.16 K, 4-hexylbenzoic acid, between 347.08 K and 363.14 K, 4-heptylbenzoic acid, between 353.16 K and 369.20 K and 4-octylbenzoic acid, between 356.67 K and 371.86 K. From the temperature dependence of the vapour pressure of the crystalline compounds, the standard, pdegrees = 10(5) pa, molar enthalpies, entropies and Gibbs energies of sublimation at T = 298.15 K, were derived. A d.s.c. study of the crystalline polymorphic transitions, fusion and isotropization of liquid crystals is also presented.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8