Half-Cell
| Formula / Notation | E = E° − (RT/nF)lnQ |
|---|---|
| Also Known As | Half-cell, electrode half-reaction, electrochemical half-cell |
What is Half-Cell?
One half of an electrochemical cell, consisting of an electrode in contact with an electrolyte solution. The half-cell reaction involves either oxidation (at the anode) or reduction (at the cathode). The cell potential is the sum of the two half-cell potentials.
Formula & Notation
Other Names / Synonyms: Half-cell, electrode half-reaction, electrochemical half-cell
Properties & Characteristics
Uses & Applications
Safety Information
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
Key Facts
Frequently Asked Questions
One half of an electrochemical cell, consisting of an electrode in contact with an electrolyte solution. The half-cell reaction involves either oxidation (at the anode) or reduction (at the cathode). The cell potential is the sum of the two half-cell potentials.
Half-cell concepts are foundational in electrochemistry: designing galvanic cells and batteries, calculating equilibrium constants from E°, potentiometric pH measurement (glass half-cell vs. reference half-cell), and understanding electrode reactions in electrolysis and corrosion.
Handling half-cell electrolytes containing toxic ions (Hg²⁺ in calomel electrode, Ag⁺, Pb²⁺) requires care. Mercury-based reference electrodes are being replaced by less toxic alternatives (Ag/AgCl). Concentrated acid electrolytes in half-cells are corrosive.
The formula or notation for Half-Cell is: E = E° − (RT/nF)lnQ