Monday, December 15, 2014

Overview Of Oxygen For Energy

By Lucia Weeks


Elemental oxygen occurs predominantly in form of a covalent homodimer on, that is a compound of two O2 atoms and having the empirical formula O2, referred to as molecular oxygen or dioxygen. There is a colorless and odorless gas that is contained in air to 20.942%. It is involved in many combustion and corrosion processes (oxygen for energy).

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.

Even in so-called main sequence stars like the sun plays a role in energy oxygen. In CNO cycle (CNO cycle) represents O2 is an intermediate of nuclear reaction in which proton capture by a 12C nucleus, which acts as a catalyst, a 4He nucleus (alpha particle) is produced. In extremely heavy stars occurs in late stage of their development to O2 burning, in which the O2 is used as nuclear fuel for reactions that lead to construction of even heavier nuclei.

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.

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.

O2 is the most abundant and widespread element on earth. It occurs both in atmosphere and in lithosphere, hydrosphere and biosphere. O2 has a mass fraction of 50.5% of earth's crust (up to 16 km depth, including hydro and atmosphere). In air, his mass fraction is 23,16% (by volume: 20.95%), the water 88.8% (the sea water but only 86%, since there large amounts salts, eg. As sodium chloride are dissolved).

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: