Dioxygen is a diatomic molecule made up of two oxygen atoms . Oxygen is part of numerous minerals, water and all living things, free is found in the atmosphere forming dioxygen molecules. Knowledge of the properties and applications of this substance allow us to assess its importance for man and the need for its conservation on the planet.
Summary
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- 1 History of the discovery of dioxygen
- 2 Properties
- 3 Applications
- 4 Sources
Dioxygen discovery story
Dioxygen was discovered by the English scientist J. Pristley ( 1733 – 1804 ) in 1774 calling it dephlogistic air due to his addiction to the phlogiston theory . He argued that the inflammation of the splinter in the air atmosphere was a purely causal phenomenon and considered that it was a mixture of nitric acid , earth and phlogiston . Two years earlier, in 1772 , this substance had already been discovered by the Swedish chemist C. Scheele ( 1742 – 1786 ) who named it incendiary air, but the information of its discovery did not immediately publish it.
In 1775 the French chemist Lavoisier , from the combustion carried out with the metallic oxides and specifically with the mercury oxide with carbon, obtained the dioxide. The gas obtained, according to him, constituted the purest part of the air. In his information the Academy called it highly breathable air or life-giving air.
The simultaneous discovery, in different countries, of this substance led to discussion about the priority of its discovery. Pristley and Scheele assiduous defenders of the phlogiston theory made it impossible for them to understand the essence of what was found and did not understand what they had discovered, so Lavoisier is credited with discovering dioxygen.
Properties
Gaseous chemical element, symbol O, atomic number 8 and atomic weight 15,994. It is of great interest for being the essential element in the respiration processes of most living cells and in the combustion processes. It is the most abundant element in the earth’s crust . About a fifth (by volume) of the air is oxygen .
Non-combined gaseous oxygen usually exists in the form of diatomic molecules, O2, but it also exists in triatomic form, O3, called ozone .
Under normal conditions oxygen is a colorless, odorless and tasteless gas; it condenses into a light blue liquid. Oxygen is part of a small group of slightly paramagnetic gases, and is the most paramagnetic of this group. Liquid oxygen is also slightly paramagnetic.
Oxygen is separated from the air by liquefaction and fractional distillation . The main applications of oxygen in order of importance are: 1) smelting, refining and manufacturing of steel and other metals; 2) manufacture of chemical products by controlled oxidation; 3) rocket propulsion; 4) support for biological life and medicine, and 5) mining, production and manufacture of stone and glass products. There are ozone generating equipment, which are used for oxidation of materials, for ozonation of swimming pools …
Almost all chemical elements, except inert gases, form compounds with oxygen. Among the most abundant binary compounds of oxygen are water , H2O, and silica , SiO2; main component of the arena. Of the compounds that contain more than two elements, the most abundant are silicates , which make up most of the rocks and soils. Other compounds that are abundant in nature are calcium carbonate (limestone and marble), calcium sulfate (gypsum), aluminum oxide (bauxite) and various iron oxides , which are used as a source of the metal.
Every human being needs oxygen to breathe, but as with many substances, an excess of oxygen is not good. If you are exposed to large amounts of oxygen for a long time, lung damage can occur. Breathing 50-100% oxygen at normal pressure for a long period of time causes damage to the lungs. People who experience frequent or potentially high exposures to pure oxygen at work should have a lung function check before and after performing that job.
Oxygen is normally stored at very low temperatures and therefore special clothing should be worn to prevent freezing of body tissues .
Oxygen can form a wide variety of different ions and oxidation states :
– OXIDE, O2− oxidation state -2
– Peroxide, O22− oxidation state -1
– Superoxide, O2− oxidation state -1/2
– Ozonide, O3 – oxidation state -1/3
– Combinations with fluorine , unique with oxygen in a positive oxidation state:
(F2O2): Oxidation state +1.
(F2O1): Oxidation state +2.
Applications
The oxygen breathed by aerobic organisms , released by plants through photosynthesis , participates in the conversion of nutrients into energy (ATP) and is essential for life. All cells in the human body require oxygen in order to live. Its decrease causes hypoxiaand the total lack of it anoxia, which can cause the death of the organism. Large amounts of oxygen are used in torches to weld at high temperatures, in which the mixture of oxygen and other gas produces a flame with a temperature much higher than that it is obtained by burning gases in air. Oxygen is administered to patients with respiratory problems and also to people flying at high altitudes, where low air pressure does not allow normal breathing. Oxygen enriched air is used to make steel in open hearth furnaces. High purity oxygen is used in the metal fabrication industry. It is very important as a propellant liquid in drones and rockets .
