The sublimation of argon, krypton, and xenon

In this paper, the sublimation pressure of Ar, Kr, and Xe are obtained as functions of temperature from an exactly integrated form of the Clapeyron equation. No fitting to experimental data of the equilibrium pressure has been necessary. The deviation plots of the sublimation pressure show that the results are satisfactory. The derived enthalpy of sublimation of the three rare gases from T = 0 K up to their respective triple point temperatures are asymmetric, distorted parabolas showing maxima for C-p,m(g) C-p,m(s). The Delta H-g(s)m (T = 0 K), which is a measure of the cohesion energy of the solid crystals, is easily calculated. A general equation has been obtained for Delta H-g(s)m, as a function of temperature which also gives the enthalpies of sublimation of neon and radon. The (s + l + g) triple point coordinates of Rn are reassessed. (C) 2008 Elsevier Ltd. All rights reserved.