The thermodynamic characteristics of sublimation and vaporization of germanium tetraiodide

Vapor pressure over solid and liquid germanium tetraiodide was measured in the temperature range 383.5-613 K by the static method in membrane null-man ometers. The temperature dependences of the heat capacities of the solid an d liquid phases determined earlier were used to calculate the thermodynamic characteristics of sublimation, fusion, and vaporization of germanium tetr aiodide by the second (II) and third (III) laws of thermodynamics. The calc ulations gave Delta(s)H(o)(298.15) = 87.1 +/- 3 (III), 86.7 +/- 6 (II) kJ/m ol; Delta(s)S(o)(298.15) = 163.95 +/- 1 (III), 163.05 +/- 3.5 (II) J/(mol K ); Delta(v)H(o)(419) = 64.2 +/- 0.1 (III), 64.5 +/- 0.2 (II) kJ/mol; Delta( v)S(o)(419) = 108.1 +/- 1 (III), 108.6 +/- 0.3 (II) J/(mol K); and Delta(fu s)H(o)(419) = 19.0 +/- 3.5 kJ/mol.