# The Thermodynamics of Chromatography - Thermodynamics Basics > Page 3

Thus, the standard energy change is made up of an actual energy or standard enthalpy change resulting from the intermolecular forces between solute and stationary phase and a standard entropy change that reflects the resulting restricted movement, or loss inrandomness, of the solute while preferentially interacting with the stationary phase.

From,
equations (1) and (2), substituting for (DG^{o} )

RT ln (K) = -DG^{o} = -DH^{o}+ TDS^{o}

Thus, (3)

_{ }

_{ or
} (4)

It might be
assumed from equation (3) that it would be relatively easy to calculate the
retention volume of a solute from the distribution coefficient, which, in turn,
could be calculated from a knowledge of the standard enthalpy and standard
entropy of the specific distribution. However, the thermodynamic properties of
a distribution system are *bulk* properties, and as such, they represent,
in a single measurement, the net effect of a number of different types
interactions which, at the present time (except for dispersive interactions)
are almost impossible to separate, identify and assess quantitatively.