Medical Laboratory Scientist ASCP Practice Exam 2025 – Complete Study Guide

The primary mechanism behind the measurement of chloride in coulometry involves the electrochemical reduction of chloride ions. In this method, chloride ions in the sample are titrated with a known quantity of silver ions. The process occurs as silver ions are generated through electrolysis and react with the chloride ions to form a precipitate of silver chloride.

During this reaction, the amount of silver ions generated is directly proportional to the amount of chloride present in the sample, allowing for accurate quantification. This titration is closely monitored to determine when all the chloride ions have reacted with the silver ions, marking the endpoint of the measurement.

In contrast, while potentiometric detection might be employed in other types of ion measurements, it does not describe the continuous electrolysis and generation of ions seen in coulometry. Similarly, conductometric measurement focuses on the overall ionic conduction of the solution rather than the specific targeted titration of chloride. Thus, the electrochemical reduction of chloride to form the corresponding precipitate is the mechanism that defines chloride measurement via coulometric methods.