In fact, some may rebound others may communicate their excess energy to another solute molecule which will give it sufficient energy to enter the mobile phase.

In either case, the net effect is the same; there will be no net molecule transfer if its energy is too great.

Under equilibrium conditions,

N1 = N2

This description of the dynamics of solute equilibrium is oversimplified, but is sufficiently accurate for the reader to understand the basic principles of solute distribution between two phases.

Consider distribution between a gaseous mobile phase and a liquid stationary phase. As the temperature is raised the energy distribution curve in the gas moves to a higher range of energies. Thus, as the column temperature is increased, more solute molecules in the stationary phase will randomly acquire sufficient energy (EA) to leave the stationary phase and enter the gas phase. Thus, the distribution coefficient of all solutes with respect to the stationary phase will be reduced as the temperature rises and it will be seen in due course that this will cause the band velocity of all the solutes to be increased.