Standard enthalpies, entropies, and Gibbs functions of sublimation of four alkyl-substituted malonic acids

• Type: Article in International Scientific Journal
• Date: 2000

Authors

da Silva, MAVR (Author) FCUP; Monte, MJS (Author) FCUP; Ribeiro, JR (Author) Other

Journal

Title: Journal of Chemical & Engineering Data

Vol. 45

Pages: 756-759

ISSN: 0021-9568

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 11 Citations

Scopus - 11 Citations

Scientific classification

FOS: Engineering and technology > Chemical engineering

Other information

Authenticus ID: P-000-Z45

DOI: 10.1021/je000090n

Abstract (EN): The Knudsen mass-loss effusion technique was used to measure the vapor pressures at different; temperatures of the following crystalline dicarboxylic acids: methylmalonic acid, between 341.13 K and 354.74 K, dimethylmalonic acid, between 347.18 K and 363.26 K, methylmalonic acid, between 347.52 K and 362.34 K and butylmalonic acid, between 348.20 K and 362.18 K. From the temperature dependence of the vapor 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 (pressure p(0) = 10(5) Pa) molar enthalpies, entropies and Gibbs functions of sublimation at T = 298.15 K, were derived.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 4