Determination of the dissociation energy of selenium monoxide by the mass-spectrometric knudsen-cell method

Abstract

The equilibrium SeO(g)+ SeS(g)⇌ Se₂(g)+ SO(g) has been studied by the mass-spectrometric Knudsen-cell method in the temperature interval 1300–1800 K. It leads to the thermochemical value D^°₀(SeO)= 426.4 ± 6.3 kJ mol^–1 for the dissociation energy of the molecule SeO(g). By comparison with spectroscopic data, D^°₀(SeO)= 424.7^+0.6_–6.0 kJ mol^–1 is retained as best present estimate of the dissociation energy. The corresponding enthalpy of formation from the elements in their standard reference states is ΔH°(formation, SeO, g, 298 K)= 58.9^+0.8_–6.0 kJ mol^–1.