In potentiometric measurements, the voltage difference between the indicator and reference electrodes is proportional to:

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Quizplus · Accepted Answer

The logarithmic relationship between cell potential and analyte activity is the basis of the ion-selective electrode's use as an analytical device.Direct potentiometric measurements measure only the free, unbound ion in solution.This is known as the activity of the ion in the specimen.Ion activity can be very closely aligned with ion concentration by using calibration solutions with the approximate composition of normal plasma.

In Potentiometric Measurements, the Voltage Difference Between the Indicator and Reference