What is the cell notation for a calomel electrode?

The cell notation for a calomel electrode is represented as Hg(l) | Hg2Cl2(s) | Cl-(aq). This notation succinctly describes the components of the electrode system.

In detail, the calomel electrode consists of elemental mercury (Hg), which is in the liquid phase, and mercury(I) chloride (Hg2Cl2), commonly known as calomel, which is a solid. The aqueous chloride ion (Cl-) serves as the ionic component in the solution. This format is standard in electrochemistry, where the anode and cathode reactions are separated by a vertical line, allowing for a clear understanding of the electrode composition.

Using this notation, one can easily identify that the calomel electrode acts both as a source of chloride ions and as a reference electrode due to the stable reduction potential established by the solid calomel in contact with the mercury. The specific combination of these components is critical in many electrochemical applications, particularly in reference setups for measuring electrode potentials.