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.
Some oxygen-rich inorganic compounds such as potassium permanganate, potassium nitrate (saltpeter), potassium chlorate and potassium chromate enter upon heating or reaction with reducing agents from oxygen. A further possibility of producing O2 in laboratory, is the decomposition of hydrogen peroxide on platinum-plated nickel foil. Pure O2 can be obtained by electrolysis of 30% potassium hydroxide solution of nickel electrodes. It Hydrogen and O2 are separated.
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.
Since these orbitals are completely filled with electrons, they do not contribute to binding. From the 2p orbitals are a total of six molecular orbitals with different energy level. The orbitals have this same energy. Electrons are distributed in molecular orbitals, it comes to following breakdown of eight p-electrons. These two valence electrons determine the properties of O2 molecule. O2 has allowed a total of three and energetically accessible quantum states for the distribution of these electrons.
Occupation of energy levels of molecular orbitals of O2 in ground and excited states. In ground state the spins of two valence electrons of Hund's rule are arranged in parallel in obedience. It is a triplet state with the term symbol 3g. It is the state with the lowest energy. Through the two unpaired electrons, the two orbitals are half occupied. This caused some characteristic properties, such as the diradical character and the paramagnetism of O2 molecule.
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.
Some oxygen-rich inorganic compounds such as potassium permanganate, potassium nitrate (saltpeter), potassium chlorate and potassium chromate enter upon heating or reaction with reducing agents from oxygen. A further possibility of producing O2 in laboratory, is the decomposition of hydrogen peroxide on platinum-plated nickel foil. Pure O2 can be obtained by electrolysis of 30% potassium hydroxide solution of nickel electrodes. It Hydrogen and O2 are separated.
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.
Since these orbitals are completely filled with electrons, they do not contribute to binding. From the 2p orbitals are a total of six molecular orbitals with different energy level. The orbitals have this same energy. Electrons are distributed in molecular orbitals, it comes to following breakdown of eight p-electrons. These two valence electrons determine the properties of O2 molecule. O2 has allowed a total of three and energetically accessible quantum states for the distribution of these electrons.
Occupation of energy levels of molecular orbitals of O2 in ground and excited states. In ground state the spins of two valence electrons of Hund's rule are arranged in parallel in obedience. It is a triplet state with the term symbol 3g. It is the state with the lowest energy. Through the two unpaired electrons, the two orbitals are half occupied. This caused some characteristic properties, such as the diradical character and the paramagnetism of O2 molecule.
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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