Vapor pressure of liquid iodine

The vapor pressure of liquid iodine was measured from 116.2 to 263.20C (100.8 -- 3808.0 mm Hg) in this work. This is not only a fundamental thermodynamic property, but also very important for designing and operating the hydrogen production process by the magnesium-iodine cycle for the thermochemical decomposition of water. There were a few data below the normal boiling point (184.50C), but no data above atmospheric pressure (760 mm Hg). Experimental data below the normal boiling point were in satisfactory agreement with the literature values. The vapor pressure data were fitted by the least-squares method to the Antoine equation within an average error of 0.66% and a maximum error of 13.3 mm Hg. The normal boiling point and the latent heat of vaporization calculated from the data of this work agreed very well with literature values. The vapor pressure data were compared with estimated values by use of the acentric factor (ω) to confirm the consistency of the experimental data, and the two almost coincided. (author)