kronopotensiometri

Kronopotensiometri is an electrochemical analytical technique used to determine the concentration of electroactive species in a solution. It belongs to the group of potentiometric methods, meaning it measures potential changes over time. In a typical kronopotentiometric experiment, a constant current is applied to a working electrode, and the resulting potential difference between the working electrode and a reference electrode is recorded as a function of time.

As the electrolysis proceeds, the concentration of the electroactive species at the electrode surface decreases. When the concentration of the species near the electrode surface is depleted, the potential of the working electrode shifts dramatically to a new value where another species can be reduced or oxidized. This rapid potential change is known as a potential step or transition. The time elapsed until this potential transition occurs is directly proportional to the initial concentration of the analyte in the solution.

The characteristic curve obtained in kronopotentiometry is a plot of potential versus time. The shape and position of the potential-time curve provide information about the analyte. By analyzing the time intervals between significant potential changes, or by comparing the transition times to those of known standards, the concentration of the analyte can be quantified. This technique is particularly useful for analyzing mixtures of electroactive substances, as distinct potential transitions can often be observed for different species present. Kronopotentiometry finds applications in various fields, including environmental monitoring, pharmaceutical analysis, and industrial process control.