In elemental state, oxygen is a gas in the atmosphere and is dissolved in water. The amount of relatively reactive oxygen elemental remains constant only in long run, because O2 producing plants replace much as of aerobic breathing creatures as well as other combustion processes is used again (oxygen for energy). Without this biological cycle O2 would only occur in compounds, ie elemental O2 exists in a dynamic equilibrium.
An older method is based on chemical reactions barium oxide method. It is uneconomical due to high energy costs. For barium oxide is heated under air at 500 degrees C., the barium forms. When heated to 700 degrees C recorded earlier O2 is released by thermolysis again. Prior to development of Linde process, this method was the only way to pure O2 present.
Oxygen is not created in primordial nucleosynthesis, but is produced in relatively large amounts in giant stars by helium burning. It is first formed from three helium nuclei 12C (Triple-alpha process), which subsequently merged with another helium nucleus to 16O. 18O is formed by fusion of 4He with a 14N nucleus.
O2 is slightly soluble in water. The solubility depends on the pressure and the temperature. It increases with decreasing temperature and increasing pressure. At 0 degrees C and an O2 partial pressure of air of 212 hPa dissolve in pure water 14.16 mg / l oxygen. In oxygen-gas discharge Spectrum, the molecular orbitals of O2 are stimulated to emit light. The operating conditions are a pressure of 5-10 mbar, a high voltage of 1.8 kV, a current of 18 mA and a frequency of 35 kHz. During the recombination of ionized gas molecules, the characteristic color spectrum is emitted. In this case, a small part, caused reversibly formed by the supply of energy ozone.
Most white dwarfs, which are the final state of 97% of all stars in prior theory, exist side by helium and carbon to a large extent of oxygen. Technically O2 is today almost exclusively obtained by rectification of air. The method in 1902, first developed by Carl von Linde (Linde process) and designed by Georges Claude economically viable. Small amounts arising as a by-product in production of hydrogen by electrolysis of water.
Initially, the O2 has been accepted as a basic component for the formation of acids. Therefore, the term Oxygenium (acidifier) 1779 proposed by Lavoisier oxygen. In fact, most inorganic acids in solution of non-metal oxides in O2 water. The halogens, such as chlorine and bromine, is therefore held for a long time oxides of unknown elements. Only later was recognized that hydrogen is responsible for the acid character.
The actual separation of nitrogen and O2 by distillation in two distillation columns with different pressures. The distillation is carried out in counter-current principle, that is by the condensation heat of evaporated gas flows upward, condensed liquid drips down. Since O2 has a higher boiling point than nitrogen, it condenses readily and collects at the bottom so, nitrogen at the top of column.
The most common stable oxygen isotope 16O (99.76%), in addition still comes 18O (0.20%) and 17O (0.037%) before. In addition to the stable oxygen isotopes are still a total of 13 unstable, radioactive nuclides from 12O to 28O are known which are artificially produced. Their half lives often are only milliseconds to seconds, with two minutes 15O this case has the longest half-life, and is frequently used in positron emission tomography.
An older method is based on chemical reactions barium oxide method. It is uneconomical due to high energy costs. For barium oxide is heated under air at 500 degrees C., the barium forms. When heated to 700 degrees C recorded earlier O2 is released by thermolysis again. Prior to development of Linde process, this method was the only way to pure O2 present.
Oxygen is not created in primordial nucleosynthesis, but is produced in relatively large amounts in giant stars by helium burning. It is first formed from three helium nuclei 12C (Triple-alpha process), which subsequently merged with another helium nucleus to 16O. 18O is formed by fusion of 4He with a 14N nucleus.
O2 is slightly soluble in water. The solubility depends on the pressure and the temperature. It increases with decreasing temperature and increasing pressure. At 0 degrees C and an O2 partial pressure of air of 212 hPa dissolve in pure water 14.16 mg / l oxygen. In oxygen-gas discharge Spectrum, the molecular orbitals of O2 are stimulated to emit light. The operating conditions are a pressure of 5-10 mbar, a high voltage of 1.8 kV, a current of 18 mA and a frequency of 35 kHz. During the recombination of ionized gas molecules, the characteristic color spectrum is emitted. In this case, a small part, caused reversibly formed by the supply of energy ozone.
Most white dwarfs, which are the final state of 97% of all stars in prior theory, exist side by helium and carbon to a large extent of oxygen. Technically O2 is today almost exclusively obtained by rectification of air. The method in 1902, first developed by Carl von Linde (Linde process) and designed by Georges Claude economically viable. Small amounts arising as a by-product in production of hydrogen by electrolysis of water.
Initially, the O2 has been accepted as a basic component for the formation of acids. Therefore, the term Oxygenium (acidifier) 1779 proposed by Lavoisier oxygen. In fact, most inorganic acids in solution of non-metal oxides in O2 water. The halogens, such as chlorine and bromine, is therefore held for a long time oxides of unknown elements. Only later was recognized that hydrogen is responsible for the acid character.
The actual separation of nitrogen and O2 by distillation in two distillation columns with different pressures. The distillation is carried out in counter-current principle, that is by the condensation heat of evaporated gas flows upward, condensed liquid drips down. Since O2 has a higher boiling point than nitrogen, it condenses readily and collects at the bottom so, nitrogen at the top of column.
The most common stable oxygen isotope 16O (99.76%), in addition still comes 18O (0.20%) and 17O (0.037%) before. In addition to the stable oxygen isotopes are still a total of 13 unstable, radioactive nuclides from 12O to 28O are known which are artificially produced. Their half lives often are only milliseconds to seconds, with two minutes 15O this case has the longest half-life, and is frequently used in positron emission tomography.
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