Saturated Calomel Electrode
Definition and meaning of Saturated Calomel Electrode in chemistry.
The saturated calomel electrode (SCE) is a highly reliable and widely used reference electrode based on the reaction between elemental liquid mercury and solid mercury(I) chloride in a saturated aqueous solution of potassium chloride.
In more detail
It provides a highly stable and completely reproducible electrode potential, making it a universal standard reference point for measuring the potentials of other working electrodes in various electrochemical cells. The standard potential of the SCE is precisely +0.241 V versus the standard hydrogen electrode at 25 degrees Celsius. Its robust physical design and general ease of use make it a staple in potentiometric measurements, corrosion studies, and cyclic voltammetry experiments.
Key facts
| Field | Analytical Chemistry |
|---|---|
| Formula | Hg2Cl2 |
| Potential | +0.241 V vs SHE |
An SCE is very frequently utilized as the stable reference electrode in a standard three-electrode setup for cyclic voltammetry experiments to accurately determine the redox properties of an unknown compound.
Frequently asked questions
What is considered a major environmental drawback of using the SCE?
It contains highly toxic liquid mercury, which has led to its gradual replacement by the more environmentally friendly silver/silver chloride reference electrode in many modern laboratories.