Electrochemistry is the area of chemistry dealing with the interconversion of electrical energy and chemical energy. There are many applications of this in every day life. Batteries, control of corrosion, metallurgy and electrolysis are just a few examples of the applications of electrochemistry. This handout will look at the basic principles of electrochemistry and show some of its applications.
Electrochemistry always involves an oxidation-reduction process. Recall that oxidation involves the loss of electrons by a substance and that reduction involves the gain of electrons by a substance. You can’t have one process without the other. The substance that is reduced is the oxidizing agent. This makes sense, because how you define an oxidizing agent – a compound that is able to oxidize another substance by removing electrons from that substance. Since the oxidizing agent is gaining the electrons that it pulls off the substance it is oxidizing, the oxidizing agent becomes reduced during the process. Similarly, the substance that is oxidized is the reducing agent. A reducing agent is a compound that will reduce another substance by giving away its own electrons to the substance it is reducing. Thus, since the reducing agent is losing those electrons, it becomes oxidized during the process. It is important to be able to determine the oxidation states of the compounds involved in an electrochemical process so as to identify which substance is oxidized and which substance is reduced.