Introduction to Stoichiometry

Electrochemistry, the study of the exchange between electrical and chemical energy, has important applications in everyday life stretching from the battery that powers your portable radio to the electrorefining that produces the copper pipes carrying your drinking water. Those electrochemical processes utilize oxidation and reduction reactions. An oxidation involves the loss of one or more electrons from a chemical species while a reduction is the gain of one or more electrons by a chemical species. When an oxidation and a reduction are paired together in a redox reaction, electrons can flow from the oxidized species, the reducing agent or reductant, to the reduced species, the oxidizing agent or oxidant. That electron flow can either be spontaneously produced by the reaction and converted into electricity, as in a galvanic cell, or it can be imposed by an outside source to make a non-spontaneous reaction proceed, as in an electrolytic cell. The following SparkNotes on electrochemistry will review redox reactions, galvanic cells, electrolytic cells, and the thermodynamics of electrochemistry.