The Free Energies and Vapor Pressures of the Alkali Metals

摘要

The free energies of the diatomic alkali vapors K2, Na2and Li2are calculated from spectroscopic data, and the equilibrium constants for the dissociation into the monatomic form are computed. With the aid of these constants, equations are deduced from the observed vapor pressures obtained by various investigators, which give the partial pressures of atoms and molecules in the saturated vapors for temperatures up to the normal boiling point. In the case of sodium and potassium, the entropy of the solid metal is computed from the vapor pressure equation, and is compared with that predicted by the third law of thermodynamics.