Pulse polarography: Part VII. Theoretical relationships for electrode processes with an ECE mechanism

A theoretical study of the pulse polarographic response for the instantaneous limiting current with an ECE mechanism is presented. Thus, equations for the current have been derived under the following conditions: (a) Both the expanding plane electrode and the expanding sphere electrode models have been accounted. (b) The steady-state approximation was not used. (c) All species are initially present in the solution. With these conditions we have: (a) proposed a method for the calculation of the rate constant values through measurements of instantaneous limiting currents; (b) shown that the interval of the rate constant values that can be determined is about 10³ times larger than in dc polarography; (c) checked the validity of the steady-state approximation.