An Equation for Vapor Pressure and Its Application to Molten Salts

Abstract

An equation for the vapor pressure of molten salts has been derived by combining the formula based on the harmonic oscillator model of a liquid with the modified Lindemann's equation proposed previously by one of the authors, as follows:
p=4.2×10¹³σ^3/2T^-1/2exp(-ΔH_V/NkT)
where p is the vapor pressure, σ the surface tension, ΔH_V the enthalpy of evaporation, T the absolute temperature, N Avogadro's number, and k Boltzmann's constant.
The values of the enthalpy of evaporation for various molten salts have been calculated from this equation using the experimental values of surface tension. The calculated values agreed well with experimental data within ±10%.