Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

Two equilibrium stills have been designed for measuring vapor-liquid equilibria of hydriodic acid and polyhydriodic acid. The acids are so corrosive that the devices must be made of corrosion resistant materials. For the HI + H2O binary system, a still has been made of tantalum and Hastelloy and operated under pressure. For the HI + H2O + I2 ternary system, another still has been made of glass and operated at atmospheric pressure. With these devices, VLE data of hydriodic acid have been acquired. The experimental conditions for the binary system were as follows: the pressure range was from (0.11 to 0.58) MPa; the HI mole fraction range in the liquid was from 0 to 0.157; and the temperature range was from (375 to 456) K. For the ternary system, the pressure was atmospheric pressure; the HI concentration in the liquid was close to the azeotrope; the HI to I2 mole ratio in the liquid range was from 1/0 to 1/4; and the temperature range was from (396 to 408) K.