Total vapor pressures of As2Se3 and As2Te3 were measured by the torsion-effusion method, and their temperature dependences were found to fit the following equations: As2Se3(s), log(p/kPa) ) (12.20 ( 0.20) to (9170 ( 130)/(T/K) and As2Te3(s), log(p/kPa) ) (10.45 ( 0.20) to (8185 ( 150)/(T/K). Considering the complex mode of vaporizing of As2Se3, the mean second-law enthalpy and entropy values associated to the sublimation of 1 mol of the vapor mixture at the mid-point temperature, centsHdeg (587 K) ) (175 ( 3) kJamol-1 and centsSdeg (587 K) ) (233 ( 4) JaK-1amol-1, were calculated from the temperature dependence of its vapor pressure. As2Te3 dissociates upon sublimation yielding As4(g) and Te(s). Both As4(g) and Te2(g) are present in the vapor over Te-saturated As2Te3, where the Te2(g) partial pressures are considered equal to the vapor pressure of the pure element. On this basis, treating the pressure data by second- and third-law methods, the standard sublimation enthalpy associated to the sublimation reaction, As2Te3(s) ) 0.5 As4(g) + 3 Te(s), centsHdeg (298 K) ) 81 ( 2 kJamol-1, was determined.
Compounds
#
Formula
Name
1
As2Se3
arsenic triselenide
2
As2Te3
arsenic telluride As2Te3
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.