Oxygen

Products

Oxygen is commercially available in the form of compressed gas cylinders (oxygen cylinders) with a white color as a compressed gas. In many countries, it is available from PanGas, for example.

Structure and properties

Oxygen (symbol: O, elemental: O2, atomic number: 8, atomic mass: 15,999) is present as dioxygen (O2, O=O) as a colorless, tasteless, and odorless gas that is sparingly soluble in water. This water solubility is important for aquatic animals such as fish. Liquid oxygen has a light blue color. The boiling point, the temperature of transition from liquid to gaseous oxygen, is -183°C. Oxygen is the best known oxidizing agent. It usually accepts two electrons and is reduced in the process. It forms oxides or dioxides with many other elements. Metals, for example, give up electrons that are taken up by oxygen. In the formation of magnesium oxide, two electrons are transferred from elemental magnesium to oxygen:

  • 2 Mg: (elemental magnesium) + O2 (oxygen) 2 MgO (magnesium oxide)

See also under redox reactions. Metal oxides (examples):

  • Iron: Iron oxides (rust)
  • Magnesium: magnesium oxide
  • Calcium: calcium oxide
  • Aluminum: aluminum oxide

Metal oxides are solids that react with water in a basic manner. Solid, liquid or gaseous oxides can be formed with nonmetals. Oxidation of nonmetals:

The combustion of organic compounds is important for energy production, for example, with methane gas, the component of natural gas:

  • CH4 (methane) + 2 O2 (oxygen) CO2 (carbon dioxide) + 2 H2O (water)

Known the also the explosive reaction with hydrogen, the oxyhydrogen reaction:

  • 2 H2 (hydrogen) + O2 (oxygen) 2 H2O (water = dihydrogen monoxide)

Most oxidations with oxygen are exothermic, meaning that energy, light and heat are released. Conversely, oxygen can also be obtained from water with the help of electrolysis. As already mentioned, oxygen is available in compressed gas cylinders. In the laboratory, it can also be obtained from oxidizing agents such as potassium chlorate or sodium chlorate by heating, as these release oxygen when heated. Plants produce oxygen as a “waste product” during photosynthesis under the influence of light:

  • 6 CO2 (carbon dioxide) + 6 H2O (water) C6H12O6 (glucose) + O2 (oxygen)

In humans, this reaction proceeds in the opposite direction, releasing energy.

Effects

Oxygen (ATC V03AN01) is essential for life. Not only because it is essential in mitochondria as an oxidant for the synthesis of the energy carrier adenosine triphosphate. But also because oxygen is one of the 6 chemical elements that make up over 99% of the body mass. The proportion of oxygen is about 60%. It is present in almost all important biomolecules, for example in amino acids, proteins, carbohydrates, nucleic acids, lipids and vitamins. This is also due to the fact that it occurs in many functional groups, for example, in alkools, aldehydes, carboxylic acids, ethers, esters and ketones. It is also present in many inorganic salts – and, of course, in water. Air is a gas mixture that consists of only about 21% oxygen. And oxygen is also present in most minerals and rocks, for example as silicon dioxide in quartz or as calcium carbonate in limestone. Silicon has a high affinity for oxygen. In the body, oxygen diffuses from the lungs into the bloodstream, where it is taken up by hemoglobin in red blood cells and transported to peripheral tissues.

Indications

  • Oxygen is administered in medicine mainly for the prevention and treatment of hypoxic and hypoxemic conditions, for example, respiratory disorders, cardiovascular disease, or shock. It also plays an important role in anesthesia.
  • In pharmacy, oxygen is contained in numerous active ingredients and excipients.
  • As a disinfectant, for example, in the form of hydrogen peroxide (release of oxygen).

Decomposition of hydrogen peroxide:

  • 2 H2O2 (hydrogen peroxide) 2 H2O (water) + O2 (oxygen)

The decomposition can be stopped by the addition of a catalyst such as manganese dioxide (MnO2) can be accelerated.

Dosage

According to the SmPC. Oxygen is administered by inhalation. During treatment, arterial oxygen pressure (PaO2) or arterial oxygen saturation (pulse oximetry) should be monitored.

Abuse

Oxidizing agents such as potassium nitrate, ammonium nitrate, and potassium chlorate can be misused for the illegal manufacture of explosives. They provide the oxygen needed for the explosive reaction to form gases.

Contraindications

For complete precautions, see the drug label.

Adverse effects

Excessive concentrations of oxygen are toxic to humans, toxic to cells, and life-threatening. Oxygen, as an oxidizing agent, has fire-promoting properties. It can start or intensify fires because oxidations occur more efficiently at a higher concentration. This can be illustrated with a glowing wood chip that begins to burn when exposed to high levels of oxygen. Oxygen cylinders containing the compressed gas can explode when heated.