The Thermodynamics of Chromatography - Interactions Between the Atoms of Hydrogen, Carbon, Chlorine and Bromine and an Exclusively Dispersive Stationary Phase > Experimental Data > Page 40



In addition,                

where (r) is the density of the medium,
(M) is the molecular or atomic weight,
(NA) is Avogadro's Number
and (PM) is the molar (or atomic)  polarizability, noting that the number of molecules per unit volume is Nr/M.


If the dispersive interactive energy, is directly related to the standard enthalpy of interaction, then,

  Consequently,                       DHo a  Pm

The standard enthalpy for hydrogen, carbon, chlorine and bromine are plotted against their atomic polarizability and the resulting linear curve is shown in figure 15 (index of determination 0.996). There is a choice for the pertinent data for carbon. The dielectric constants of graphite and diamond are similar, but their densities are significantly different,