How much may the equilibrium be shifted in a chemical relaxation experiment? Part 2.—Two-step systems
Abstract
A simple method for determining the allowable maximum amplitude (a.m.a.) in a relaxation experiment is applied to systems with two kinetically uncoupled equilibria. This method is based on the use of factor r in the relaxation equation 1/vij= 1, defining the allowable amplitude, is discussed in connection with the signal-to-noise ratio of experimental signals. In favourable cases large values of r can be used if the relaxation times are corrected. By applying this method to an acid–base equilibrium in a buffer, or coupled with an indicator, it can be shown that linearity can be excellent even for large perturbations in many practical cases.