Thermodynamic study on the sublimation of 1,2-diphenylethane and of 3-phenylpropiolic acid

✍ Scribed by Manuel J.S. Monte; Dorothea M. Hillesheim

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 108 KB
• Volume: 33
• Category: Article
• ISSN: 0021-9614
• DOI: 10.1006/jcht.2000.0761

✦ Synopsis

The Knudsen mass-loss effusion technique was used to measure the vapour pressures at different temperatures of the following crystalline compounds: 1,2-diphenylethane (bibenzyl), between T = 289.16 K and T = 303.20 K, and of 3-phenylpropiolic acid between T = 329.15 K and T = 343.15 K. From the temperature dependence of the vapour pressure, the standard molar enthalpies of sublimation at the mean temperature of the experimental range were derived by the Clausius-Clapeyron equation. From these results the standard, p o = 10 5 Pa, molar enthalpies, entropies, and Gibbs energies of sublimation at T = 298.15 K, were calculated:

1,2-Diphenylethane 93.2 ± 0.9 211 ± 3 30.2 ± 1.3 3-Phenylpropiolic acid 105.0 ± 1.4 211 ± 6 42.1 ± 2.3