Oxidation-reduction
Originally chemists viewed oxidation as a class of chemical reactions in which a chemical species (e.g., atom, ion, molecule, compound) reacts with an oxygen molecule (O2) such that it combines with an atom of oxygen (O) to form an oxygen-containing product, as when hydrogen (H2) reacts with O2 to form the oxygen-containing product, H2O, namely water:
- 2H2 + O2 → 2H2O
In that reaction, each molecular pair of hydrogen atoms was described as having been 'oxidized' by gaining an oxygen atom, forming a chemical compound referred to as an 'oxide', in this case dihydrogen oxide.
The 'Father of Chemistry', Antoine-Laurent Lavoisier (1743-1794), in his Elements of Chemistry (originally published in French in 1789), writes of oxidation in relation to the products formed when metals (e.g., iron) are exposed to air:
The term oxidation, or calcination, is chiefly used to signify the process by which metals exposed to a certain degree of heat are converted to oxides, by absorbing oxygen from the air.[1]
Lavoisier's work revealed the common link between the air-requiring processes of burning (combustion), rusting and other such so-called calcinations of metals, and breathing (respiration) by animals, namely the requirement for the oxygen component of air and the chemical reaction of oxidation.
References
- ↑ Lavoisier AL. (1799) Elements of chemistry: in a new systematic order, containing all the modern discoveries, illustrated with thirteen copperplates. Translated by Robert Kerr. 4th edition. | Google Books free full-text.