On the Description of Rate Processes by Means of Relaxation Times

Attention is drawn to the importance of recognizing the various relaxation times associated with a single relaxation mechanism. The physical origin of the differences between the relaxation times is indicated and the relationships between them are illustrated by examples. A general formula is derived which relates the relaxation times for a single mechanism under different thermodynamic constraints. Connection is established between chemical rate constants and relaxation times. It is concluded that there is no intrinsic relaxation time derivable on a kinetic basis without reference to the thermodynamic conditions under which the relaxation takes place.