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.
Almost all living organisms need O2 to live (typically give plants during photosynthesis but more O2 from than they consume). You see him mostly by breathing in air, or by absorption of water (dissolved oxygen). In high concentrations, however, it is toxic to most living things.The metastable, high-energy and reactive allotrope of three O2 atoms (O3) is called ozone. Atomic oxygen, ie O2 in form of free, single O2 atoms, is stable before only under extreme conditions, such as in vacuum of space or in hot stellar atmospheres. However, it has a significant meaning as a reactive intermediate in many reactions of atmospheric chemistry.
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.
This promoted the combustion gas and Scheele called it "fire air" or the origin. He found that air consists of O2 and this "foul air". Completely independent, was two years later produced by heating mercuric oxide O2 gas, the Englishman Joseph Priestley. The Briton published his findings in 1774, Scheele published his book Chemical Observations of air and the fire but only in 1777.
The binding and the properties of O2 molecule can be well explained by the molecular orbital model. The s and p atomic orbitals of individual atoms are assembled to form bonding and antibonding molecular orbitals. The 1s and 2s orbitals of O2 atoms are each to . Sigma.. Sub. S and . Sigma.. Sub. S - bonding and antibonding molecular orbitals.
For O2 recovery after Claude process air by means of compressors to 5-6 bar is compressed, cooled and then removed by first filter of carbon dioxide, humidity, and other gases. The compressed air is cooled by flowing past gases from the process to a temperature near the boiling point. It is then expanded in turbines. A portion of energy used for compression can again be recovered. This is the method -. In contrast to Linde process, in which no energy is recovered - a lot more efficient.
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.
Almost all living organisms need O2 to live (typically give plants during photosynthesis but more O2 from than they consume). You see him mostly by breathing in air, or by absorption of water (dissolved oxygen). In high concentrations, however, it is toxic to most living things.The metastable, high-energy and reactive allotrope of three O2 atoms (O3) is called ozone. Atomic oxygen, ie O2 in form of free, single O2 atoms, is stable before only under extreme conditions, such as in vacuum of space or in hot stellar atmospheres. However, it has a significant meaning as a reactive intermediate in many reactions of atmospheric chemistry.
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.
This promoted the combustion gas and Scheele called it "fire air" or the origin. He found that air consists of O2 and this "foul air". Completely independent, was two years later produced by heating mercuric oxide O2 gas, the Englishman Joseph Priestley. The Briton published his findings in 1774, Scheele published his book Chemical Observations of air and the fire but only in 1777.
The binding and the properties of O2 molecule can be well explained by the molecular orbital model. The s and p atomic orbitals of individual atoms are assembled to form bonding and antibonding molecular orbitals. The 1s and 2s orbitals of O2 atoms are each to . Sigma.. Sub. S and . Sigma.. Sub. S - bonding and antibonding molecular orbitals.
For O2 recovery after Claude process air by means of compressors to 5-6 bar is compressed, cooled and then removed by first filter of carbon dioxide, humidity, and other gases. The compressed air is cooled by flowing past gases from the process to a temperature near the boiling point. It is then expanded in turbines. A portion of energy used for compression can again be recovered. This is the method -. In contrast to Linde process, in which no energy is recovered - a lot more efficient.
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.
About the Author:
You can visit boostcanada.ca for more helpful information about Guide To Oxygen For Energy.
0 comments:
Post a Comment