Thermodynamic Properties of Gas-Phase Potassium Sulfide Species

The free energies of formation at 0 K of gas phase KS and K//2S have been estimated to be 29. 0 and minus 13. 3 kcal mol** minus **1, respectively. The important physical and spectroscopic properties of these species have also been estimated so that the equilibrium vapor pressure and composition over condensed K//2S can be calculated as a function of temperature. Such calculations indicate that K//2S should be an important species in the vapor phase above K//2S (s, 1), in agreement with qualitative mass spectrometric observations. Thermodynamic tables are presented, and the importance of the present results to MHD sulfur removal is briefly discussed.