Voltaic Cells
Definition and meaning of Voltaic Cells in chemistry.
Voltaic cells, also commonly known as galvanic cells, are electrochemical devices that reliably generate electrical energy directly from spontaneous oxidation-reduction chemical reactions.
In more detail
These functional cells physically consist of two different solid metals, called electrodes, that are separately immersed in appropriate electrolyte solutions and connected by both an external electrically conductive circuit and an internal salt bridge. A spontaneous chemical redox reaction occurs where electrons are continuously lost at the anode electrode through the process of oxidation and subsequently gained at the cathode electrode through the process of reduction. The directed flow of these negatively charged electrons through the external metal wire circuit creates a usable electric current that can easily perform mechanical or electrical work. The internal salt bridge crucially completes the entire circuit by allowing non-reactive ions to migrate between the solutions, continuously maintaining electrical neutrality within both separate half-cells.
Key facts
| Field | General Chemistry |
|---|---|
| Primary Function | Converts chemical energy into usable electrical energy |
| Anode Process | Chemical oxidation |
| Cathode Process | Chemical reduction |
A standard zinc-copper voltaic cell uses a solid zinc anode placed in a zinc sulfate solution and a solid copper cathode placed in a copper sulfate solution to spontaneously generate an electrical potential of approximately 1.1 volts.
Frequently asked questions
What is the primary difference between a voltaic cell and an electrolytic cell?
A voltaic cell spontaneously generates free electricity from a natural chemical reaction, while an electrolytic cell strictly requires an external source of electrical energy to forcefully drive a non-spontaneous reaction.