Coulometry at an imposed, constant electric current in the
electrochemical cell.
Notes: - Direct coulometry at controlled current is usually carried out in convective mass transfer mode. The end-point of the electrolysis, at which the current is stopped, must be determined either from the inflection point in the \(E{-}t\) curve or by using visual or objective end-point indication, similar to volumetric methods. The total electric charge is calculated as the product of the constant current and time of electrolysis or can be measured directly using a coulometer.
- The advantage of this method is that the electric charge consumed during the electrode reaction is directly proportional to the electrolysis time. Care must be taken to avoid the potential region where another electrode reaction may occur.
Source:
PAC, 2020, 92, 641. 'Terminology of Electrochemical Methods of Analysis (IUPAC Recommendations 2019)' on page 683 (https://doi.org/10.1515/pac-2018-0109)