Galvanic Cells and Batteries – Basic Principles
How it works
Galvanic cells are electrochemical cells in which a redox reaction can proceed in two half-cells that are spatially separated. The transfer of electrons occurs via an external conductor, thereby generating electrical energy. In simple school models, the half-cells consist of electrodes and electrolyte solutions. The voltage (electrical potential difference) results from the different redox potentials of the substances involved; it also depends on conditions such as concentration and temperature. In batteries, galvanic cells are used technically to store chemical energy and provide it as electrical energy during discharge. The anode is the electrode at which oxidation takes place, the cathode is the electrode of reduction. The circuit is closed by a salt bridge or a diaphragm, which enables charge compensation.
In a galvanic cell, oxidation takes place at the anode and reduction takes place at the cathode. The electrons move through the external circuit from the anode to the cathode. In typical metal/metal ion cells such as the Daniell cell, this usually corresponds to the path from the less noble metal to the more noble metal. Under standard conditions, the cell voltage results from the difference between the standard electrode potentials; during operation, concentrations and temperature can change the voltage.
An example
Which statement applies to the anode of a Daniell cell (Zn/Cu)?
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: Chemistry. The topic assignment may vary by federal state.