Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Vapor Pressures and Sublimation Enthalpies of Cadmium Difluoride and Zinc Difluoride by the Torsion-Effusion Method

Brunetti, B.[Bruno], Lelo, D.[Dalina], Piacente, V.[Vincenzo], Scardala, P.[Paolo]
J. Chem. Eng. Data 2008, 53, 9, 2101-2105
ABSTRACT
The vapor pressures over solid CdF2 and ZnF2 were measured by the torsion-effusion method. The temperature dependencies of the vapor pressures of these compounds were found to fit the following equations: log(p/ kPa) ) (9.55 ( 0.30) - (13920 ( 300)(T/K) (from (962 to 1149) K), and log(p/kPa) ) (9.79 ( 0.40) - (12510 ( 400)(T/K) (from (846 to 1047) K) for CdF2 and ZnF2, respectively. Treating these vapor pressures by the second- and third-law methods, the standard sublimation enthalpies AsubHdeg (298 K) ) (285 ( 10) kJ * mol-1 and (257 ( 8) kJ * mol-1 and entropies AsubSdeg (298 K) ) (163 ( 6) J *K-1 * mol-1 and (169 ( 8) J *K-1 * mol-1 for CdF2 and ZnF2, respectively, were calculated.
Compounds
# Formula Name
1 CdF2 cadmium difluoride
2 F2Zn zinc fluoride
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
  • TOREFF:UFactor:2
  • 166
  • POMD
  • 2
  • Vapor or sublimation pressure, kPa ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • TOREFF:UFactor:2
  • 183