Total vapour pressure of FeI 2 from torsion measurements

Abstract

The total vapour pressures of iron diiodide were measured by the torsion-effusion method and the temperature dependence is represented by the following equation: log {p(kPa)} = (10.80 ± 0.40) - (9860 ± 300)/T The standard sublimation enthalpy of the reaction: FeI 2(s)→FeI 2(g), Δ r H 0(298) = 194 ± 2 kJ mol −1, was obtained from second- and third-law treatments of the pressure data considering the partial pressure of FeI 2(g) equal to 0.70 p tot. Comparisons with previous results are made.