The measurement of the potential of a galvanic cell can be used to determine the concentration of the ions in a สาละลาย via the Nernst equation. The most widespread use of this analytical technique is the measurement of pH (the acidity or the concentration of hydrogen ions) in a liquid.2 For example, the combination of a standard electrode and a (nonstandard)
hydrogen electrode can be used to measure the concentration of hydrogen ions present.
The standard electrode chosen is often a calomel electrode, which is a particularly stable electrode that uses the redox couple Hg2Cl2/Hg, Cl