Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

The design, construction, and testing of a new Knudsen effusion apparatus

Ribeiro da Silva, M. A. V.[Manuel A. V.], Monte, M. J. S.[Manuel J. S.], Santos, L. M. N. B. F.[Luis M. N. B. F.]
J. Chem. Thermodyn. 2006, 38, 6, 778-787
ABSTRACT
A new Knudsen effusion apparatus, enabling the simultaneous operation of nine effusion cells at three different temperatures, is fully described. The performance of the new apparatus was checked by measuring the vapour pressures, between 0.1 Pa and 1 Pa, over ca. 20 K temperature intervals of benzoic acid, phenanthrene, anthracene, benzanthrone, and 1,3,5-triphenylbenzene. The derived standard molar enthalpies of sublimation are in excellent agreement with the mean of the literature values available for these five compounds and with the recommended values for four of them.
Compounds
# Formula Name
1 C7H6O2 benzoic acid
2 C14H10 anthracene
3 C14H10 phenanthrene
4 C24H18 1,3,5-triphenylbenzene
5 C17H10O 7H-benz[de]anthracen-7-one
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Vapor or sublimation pressure, kPa ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Calculated from knudsen effusion weight loss
  • 29
  • POMD
  • 2
  • Vapor or sublimation pressure, kPa ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Calculated from knudsen effusion weight loss
  • 31
  • POMD
  • 3
  • Vapor or sublimation pressure, kPa ; Crystal 2
  • Temperature, K; Crystal 2
  • Crystal 2
  • Gas
  • Calculated from knudsen effusion weight loss
  • 32
  • POMD
  • 4
  • Vapor or sublimation pressure, kPa ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Calculated from knudsen effusion weight loss
  • 35
  • POMD
  • 5
  • Vapor or sublimation pressure, kPa ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Calculated from knudsen effusion weight loss
  • 29