AbstractKnudsen effusion studies of the sublimation of polycrystalline SnSe and SnSe2, prepared by annealing and chemical vapor transport reactions, respectively, have been carried out using vacuum microbalance techniques in the temperature ranges 736–967 K and 608–760 K, respectively.From experimental mass‐loss data for the sublimation reaction SnSe(s) = SnSe(g), the recommended values for the heat of formation and absolute entropy of SnSe(s) were calculated to be ΔH°298,f = −86.4 ± 9.9 kJ · mol−1 and S°298 = 89.0 ± 7.1 J · K−1 · mol−1. From mass‐loss data for the decomposition reaction \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm SnSe}_{\rm 2} ({\rm s)} = {\rm SnSe(s)} + \frac{1}{{\rm x}}{\rm Se}_{\rm x} ({\rm g) (x} = 2 - 8) $\end{document}, the recommended values for the heat of formation and absolute entropy of SnSe2(s) were determined to be ΔH°298,f = −118.1 ± 15.1 kJ · mol−1 and S°298 = 111.8 ± 11.8 J · K−1 mol−1.
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