Dielectric Constants of Non-Polar Fluids. II. Analysis of Experimental Data

Although the formulas of Part I do not apply strictly to actual gases and liquids, they suggest a possibly useful method of analyzing data on the variation of dielectric constant ε with density d under high pressure at constant temperature. The method is to express (ε+2)d/(ε−1) as a polynomial in d; the variable terms represent the deviation from the Clausius-Mosotti formula. This method has been tested, and compared with alternative procedures based on more specialized formulas, by analysis of data on carbon disulfide (Chang, Danforth) and on carbon dioxide (Michels and Kleerekoper). It is concluded that the proposed method is an efficient one for representing the data, that the values of the coefficients are consistent with the approximate values estimated from the simplified theory, and that there is no advantage in the use of more specialized formulas. The precision of present ε vs. d data and of present knowledge of molecular distribution functions does not justify any more detailed conclusions.