The vapor pressures in equilibrium over HgF2 and Hg2F2 were measured by the torsion-effusion method. HgF2 vaporized congruently. The temperature dependence of the vapor pressure of this compound was found to fit the following equation: HgF2(s), log(p/kPa) ) (9.00 ( 0.30) - (6750 ( 200)(K/T) (from (496 to 629) K). Treating the vapor pressure data by the second- and third-law methods, the standard sublimation enthalpy, AsubHdeg (298 K) ) (136 ( 4) kJ * mol-1, and entropy, AsubSdeg (298 K) ) (145 ( 6) J *K-1 * mol-1, were selected. In the covered temperature range (from (457 to 589) K), Hg2F2(s) decomposes into HgF2(s) and Hg(g) so that the temperature dependence of the mercury pressure above this compound, log(p/kPa) ) (7.90 ( 0.50) - (5400 ( 300)(K/T), was determined. Also, for this compound, the standard sublimation enthalpy, AsubHdeg (298 K) ) (105 ( 4) kJ * mol-1, and entropy, AsubSdeg (298 K) ) (114 ( 10) J *K-1 * mol-1, were determined.
Compounds
#
Formula
Name
1
F2Hg
mercuric difluoride
2
F2Hg2
mercury fluoride (Hg2F2)
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.