Frohlich equation -

For experimental estimation of the correlation factor g the Kirkwood-Frohlich equation [7]... 

However, the most recent discussions favour these high values of g although values of the order of 20% lower had ori nally been favoured. This is because the Frohlich equation [equation (1)] differs from the earlier version of Kirkwood, and treats the inner field in a more nearly correct manner. It is no longer necessary to make a calculation of the HjO dipole moment in its surroundings in the liquid, as had been necessary in the application of the Kirkwood equation. The dipole moment of the free molecule, /i = 1.84D, is used in equation (1), together with = 1.80 at 293 K. This leads to a value of = 2.82, which is sufficiently close to that calculated from the computer dynamics model to warrant optimism for future calculations. The exact choice of will continue to present difficulties until the far-i.r. data are complete over a wide range of temperature. 

The static permittivities of mixtures of organic liquids with water may be interpreted in terms of polarization theory. We shall see that water can be used as a solvent for the determination of dipole moments of highly polar molecules, but for less polar molecules the Kirkwood-Frohlich equation has been used as a method of demonstrating molecular interactions between water and solute. 

From the values of resistance [K] obtained for the different investigated systems, the dc conductivity was calculated, according to the equation reported in [32] and listed in Table 7.10. After subtracting the dc losses from the measured s" values, the results showed a well-defined absorption region [Fig. 7.3) according to the Frohlich equation [33]. Table 7.11 shows these values in the... 

Reis JCR, Iglesias TP (2011) Kirkwood cwrelatirm factras in liquid rrrixtures from an extended Orrsager-Kirkwood-Frohlich equation. Phys Chem Chan Phys 13 10670-10680... 

Dielectric saturation produces "irrotational bounding of the solvent molecules surroimding the ion and hence yields solvation numbers. Pottel et al.25,58 use the empirical Bruggeman relation for the estimation of the "effective" volume fraction of the solvent. Comparision with its "analytical" value yields solvation numbeiTS Zp. Lestrade et al.30 39 use the Kirkwood Frohlich equation with the Kirkwood parameter assumed independent of electrolyte concentration, to calculate solvation numbers Zl Ly means of the number of molecules per unit volume required to explain the limiting slope of the permittivity depression. A siu vey of solvation numbers Zp and obtained from these methods and their critical discussion is given in Ref. 14. 

The Kirkwood-Frohlich equation incorporates this factor, and enables the mean square effective dipole moment to be deduced from measurements of the electric permittivity, refractive index and number density of a fluid ... 

The distortion polarizability contributes only to the refractive index, and the dielectric constant can be related to the molecular dipole moment through the Kirkwood-Frohlich equation, which in isotropic liquids reads as ... 

The static dielectric permittivity for an ensemble of dipolar chain molecules is given by the generalized form of the Kirkwood-Frohlich equation... 

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