Donor half-cell
The donor half-cell is that half-cell in a galvanic element in which the oxidation ( release of electrons ) from the reduced form of a redox couple (often a metal) to the oxidized form takes place.
It is connected to the acceptor half-cell by means of a salt bridge (ion bridge). The result is that the metal atoms of the electrode of the half-cell transform into positively charged ions and the electrode gradually dissolves. In chemistry, positively charged ions are called cations , negatively charged anions , because they migrate in an electric field as an ion current to the cathode ("negative pole" of the field) or to the anode ("positive pole" of the field). In a solvent to a form surrounding the ion solvation shell from.
The strength of an oxidizing agent can be measured by measuring the potential difference to a reference electrode. The half-cell in a galvanic element with the more negative normal potential is always the donor half-cell. The name donor comes from the fact that electrons are transferred to the other half-cell (acceptor half-cell) during oxidation.
In a Daniell element , the half-cell with the zinc electrode is the donor half-cell; zinc is oxidized to zinc ions. In a hydrogen fuel cell , hydrogen is the donor; it is oxidized to hydrogen ions by releasing electrons
See also
literature
- Michael Wächter: Book of Tables of Chemistry: Data on Analytics, Laboratory Practice and Theory , John Wiley & Sons, 2012, ISBN 978-3-527-32960-1 .
