THE CONSTRUCTION, TESTING AND USE OF A NEW KNUDSEN EFFUSION APPARATUS

• Type: Article in International Scientific Journal
• Date: 1990

Authors

DASILVA, MAVR (Author) FCUP; MONTE, MJS (Author) FCUP

Journal

Title: Thermochimica Acta

Vol. 171

Pages: 169-183

ISSN: 0040-6031

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 149 Citations

Scopus - 156 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-001-RD7

DOI: 10.1016/0040-6031(90)87017-7

Abstract (EN): The construction of a new Knudsen effusion apparatus for measuring vapour pressures of organic and organometallic solids as a function of temperature and the subsequent calculation of enthalpies of sublimation are described. The new apparatus enables the simultaneous operation of three different effusion cells, reducing, considerably, the time necessary for the study of each compound. The performance of the apparatus was checked by measuring, as a function of temperature, the vapour pressure of benzoic acid (between 307.15 and 314.15 K) and ferrocene (between 292.27 and 300.01 K), from which their standard molar enthalpies of sublimation, at 298.15 K, were derived: benzoic acid, ¿cr gH298.15 XXX = 89.25±0.85 kJ mol-1; ferrocene, ¿cr gH298.15 XXX = 72.39 ± 1.00 kJ mol-1. © 1990.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 15