Liquid zinc chloride vaporization thermodynamics by modified entrainment

The thermodynamics of the vaporization of liquid zinc chloride has been studied in the temperature range 638–978 K by the modified entrainment method. Enthalpy and entropy changes for vaporization have been derived for the monomer and dimer species. These values are unchanged in a melt contaminated with water at a mole ratio of 1%. The proportion of dimer in the saturated vapour is found to decrease with increasing temperature. The vapour pressure equations for monomer and dimer vaporization, ZnCl2(l) = ZnCl2(g) and 2ZnCl2(l) = Zn2Cl4(g) are In [p10/pӨ] = −(15300 ± 60)K/T + (15.39 ± 0.06) and In [p20/pӨ] = −(11000 ± 970)K/T + (6.5 ± 1.3) for the temperature range 640–980 K.