Vapor pressure measurements of PbBr₂ by the Knudsen effusion method and identification of its vapor species

The vapor pressure of PbBr₂ solid was measured by the Knudsen effusion method assuming that the vapor species consisted only of monomers. The vapor pressure of PbBr₂ fitted the following linear equation over the temperature range 532.3-633.9 K:ln(p(Pa))=-(16,653±431)T (K)+(26.47±0.74). The standard sublimation enthalpy of PbBr₂ was estimated to be 138.5 ± 3.6 kJ mol^-1, and the standard sublimation entropy was estimated to be 220.1 ± 6.2 J mol^-1 K^-1. Identification of the predominant vapor species of PbBr₂ was conducted using mass spectrometry. From the analysis, the main vapor species of PbBr₂ solid is the PbBr₂ monomer.