Oxidation and Reduction Chemical Reactions
Antoine Laurent Lavoisier (1743-1794) further developed the experimental work of Joseph Priestley, and applied the name oxygen to the element. When non-metallic elements such as sulphur and phosphorus are burnt, the result is an acidic gas. In Considérations Générales sur la Nature des Acides (1778), he demonstrated that the "air" responsible for combustion was also the source of acidity. He named this portion of air oxygen (Greek for acid maker), and the other azote (Greek for no life). The British scientist Humphry Davy (1778-1829) challenged Lavoisier's theory that oxygen is the principal source of acidity in 1810. Davy showed that most but not all acids contain oxygen. He went on to demonstrate that alkalis and alkaline earths are oxides.
| Metals form solid oxides. These oxides are bases |
| Non metals form solid, liquid or aqueous oxides. These oxides are acids. |
| Aluminium oxides are amphoteric which means they have some characteristics of metals and some of non-metals |
Oxidation has been explained as the addition of oxygen - this was the definition of the oxidation process given by scientists when oxidation was first being investigated. The reverse chemical process is referred to as reduction.
2H2 (hydrogen) + O2 (oxygen) -> 2H2O (water)The hydrogen is oxidised and the oxygen is reduced, so that oxidation and reduction occur together in the process.
Methane burning:
CH4 (methane) + 2O2 (oxygen) -> CO2 (carbon dioxide) + 2H2O (water)In this instance the hydrogen is reduced - oxidation can also be explained as the addition of hydrogen.
Pâte-de-verreAn opaque glass known as pâte-de-verre, with a similar appearance to alabaster is produced by manipulation of the oxidation process.
Chemistry of FireworksOxidations and reductions take place within a firework as it climbs into the night sky. Oxidisers produce the oxygen required to burn the mixture of reducing agents and to excite the atoms of the light-emitting compounds. The most commonly used oxidisers are nitrates, chlorates, and perchlorates. The reducing agents, sulphur and carbon, combine with the oxygen from the oxidisers to produce the energy of the explosion.
