The Dielectric Constant of Ammonia as a Function of Temperature and Density

Abstract

The dielectric constant of ammonia has been measured over a wide range of density at several temperatures. The Clausius-Mosotti function $\frac{(\ensuremath{\epsilon}\ensuremath{-}1)V}{(\ensuremath{\epsilon}+2)}$ was found to increase with increasing density. At the lower densities it was adequately represented by the following formula $\frac{\ensuremath{\epsilon}\ensuremath{-}1}{\ensuremath{\epsilon}+2} V =\frac{4\ensuremath{\pi}N{p}_{0}}{3}\frac{1}{1\ensuremath{-}{\ensuremath{\lambda}}_{\ensuremath{\rho}}}$where ${p}_{0}$ is the molecular polarizability, $\ensuremath{\rho}$ the density, and $\ensuremath{\lambda}$ a constant expressible in terms of the equation of state constants, $A$ and $b$, as $\frac{32{\ensuremath{\pi}}^{2}p_{0}^{2}{N}^{2}}{45b} (1 + \frac{1}{3}\frac{A}{\mathrm{bRT}})$Previous measurements of the dielectric constant of carbon dioxide are further discussed.