What happens at the cathode in an electrochemical cell?

In an electrochemical cell, the cathode is defined as the electrode where reduction takes place. Reduction involves the gain of electrons, leading to a decrease in the oxidation state of the reactants. When a species at the cathode gains electrons, it converts into a more reduced form, typically resulting in the formation of products such as metals from their ions, or other reduced chemical species.

This concept is rooted in the fundamental principles of electrochemistry, where oxidation occurs at the anode (the opposite electrode) and is characterized by the loss of electrons. The flow of electrons from the anode to the cathode through an external circuit facilitates this process, enabling the chemical reactions necessary for the electrochemical cell to function.

In summary, at the cathode, reduction is the key reaction, leading to the production of various products depending on the specific electrochemical reaction taking place. This understanding is crucial for applications in batteries, electrolysis, and other electrochemical systems.