Vapor pressure and enthalpies of vaporization of cerium trichloride, tribromide, and triiodide

The total vapor pressures of cerium trihalides CeCl3, CeBr3, and CeI3 were measured by the torsion method, and their temperature dependence can be exp ressed by the following equations over the given temperature ranges: CeCl3( s), log(p/kPa) = (12.21 +/- 0.20) - (16443 +/- 150)K/T, (955-1070) K; CeBr3 (s), log(p/kPa)= (12.12 +/- 0.20) - (15332 +/- 150)K/T, (887-1003) K; CeBr3 (1), log(p/kPa)= (9.57 +/- 0.30) - (12745 +/- 300)K/T, (1009-1172) K; CeI3( s), log(p/kPa)=(12.02 +/- 0.20) - (14843 +/- 150)K/T, (910-1031) K. Treatin g the obtained results by second- and third-law methods, the standard subli mation enthalpies, Delta(sub)H degrees (298 K)= {(331 +/- 5), (300 +/- 10), and (295 +/- 10)} kJ mol(-1) for CeCl3(s), CeBr3(s), and CeI3(s), respecti vely, were determined.