Anomalies in the log freundlich equation resulting in deviations in adsorption k values of pesticides and other organic compounds when the system of units is changed

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Abstract
Freundlich K values cannot be directly converted from one set of units to another unless the slope, N, is unity. Dimensional analysis of the Freundlich equation shows the units of K to be mol (1-N)LNg-1, instead of the commonly used units, mol/g. A mathematical relationship exists between the ratio of K values in 2 different sets of units and N. The magnitude of K does not change by the same factor as the adsorption data (x/m, C) from which it was calculated, when units are changed, unless N = 1.0. To avoid problems associated with units of K, it is recommended that mole fraction (a unitless quantity) be used to express equilibrium concentration, and that K no longer be used as an indicator of relative adsorption [in soil/water systems]. An alternate means of assessing relative adsorption among pesticides is proposed.