Thermodynamic Study of Benzamide, N-Methylbenzamide, and N,N-Dimethylbenzamide: Vapor Pressures, Phase Diagrams, and Hydrogen Bond Enthalpy

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

Authors

Ana R R P Almeida (Author) Other; Manuel J S Monte (Author) FCUP

Journal

Title: Journal of Chemical & Engineering Data

Vol. 55 No. 1

Pages: 3507-3512

ISSN: 0021-9568

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 42 Citations

Scopus - 42 Citations

Scientific classification

FOS: Engineering and technology > Chemical engineering

Other information

Authenticus ID: P-003-3J1

DOI: 10.1021/je100175j

Abstract (EN): A static method was used to measure the vapor pressures of crystalline and liquid phases of benzamide, N-methylbenzamide, and N,N-dimethylbenzamide, in the temperature ranges (344.8 to 438.2) K, (322.9 to 388.4) K, and (297.0 to 361.7) K, respectively. The vapor pressures of the crystalline phase of benzamide were also measured using the Knudsen effusion method in the temperature range (324.1 to 344.2) K. From the experimental results, the standard molar Gibbs energies and enthalpies of sublimation and of vaporization, at T = 298.15 K, and the triple points coordinates (p,T) for the three compounds were derived. The temperatures and molar enthalpies of fusion were also determined using differential scanning calorimetry and were compared with the values derived from the vapor pressure measurements. The results enabled the determination of the hydrogen bond enthalpies in the studied compounds.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6