Second Virial Coefficients and the Arsenic Vapor-Condensed Phase Equilibrium
Journal of Phase Equilibria
The published temperature-pressure-vapor density data for As can be fit to 1.07% with two-parameter second virial coefficients for As2 and As4. In contrast to the assumptions of previous analyses of the As system, the vapor already shows significant departure from ideality at 975 K and 5.5 atm. One set of these virial coefficients is used along with the SGTE database with a few small adjustments to obtain a self-consistent description of the vapor-condensed phase equilibria. The calculated vapor pressure agrees with the experimental data to within 1% between 790 and 1000 K, where experimental data are most closely established, and is in agreement with the experimental scatter between 1000 and 1200 K. The thermodynamic data established in this fitting are then used to calculate the vapor pressure up to 1600 K.
Brebrick, Robert F., "Second Virial Coefficients and the Arsenic Vapor-Condensed Phase Equilibrium" (1999). Mechanical Engineering Faculty Research and Publications. 262.