Galvanic Cells

An electrochemical reaction is a process where electrons are transferred between two substances, with one losing electrons and the other gaining them. When a substance loses electrons, we say that it has undergone oxidation or that it has been oxidized. When it gains electrons, we say that it has undergone reduction or has been reduced. To help you distinguish between the two, remember the phrase 'oil rig,' which stands for oxidation is losing, reduction is gaining. Some electrochemical reactions occur spontaneously, which we can study in a galvanic cell.

The galvanic cell has four main parts. First, there are two metal electrodes, each of which is immersed into a different electrolyte solution. The solutions consist of the ions needed for the half-reactions, either the oxidation or reduction reaction, that occur at each electrode. The solutions are connected by a salt bridge, which enables the flow of ions and maintains the charge neutrality of the solutions. The electrodes are connected by an external circuit, which the electrons travel through during the reaction.

The anode is the electrode that gives up electrons in the reaction or is oxidized. The cathode is the electrode that