Discharge chemistry, electric

Electric current, 78 Electric dipoles, see Dipoles Electric discharge, 239 Electric force, 76, 77 Electricity, fundamental unit, 241 Electrochemical cell chemistry of, 199 and Le Chatelier s Principle. 214 operation, 206 standard half cell, 21C Electrodes, 207 Electrolysis, 220, 221 apparatus, 40 cells, 238 of water, 40, 115 Electrolytes, 169, 179 strong, 180 weak,180... 

Radiation Chemistry and Electric Discharge Chemistry Comparison and Contrast... 

This is a particularly good place to emphasize a point implied by the Introduction. Although the special importance of vibrationally highly excited species in discharge chemistry may be easily invoked, we must at the same time not neglect the totality of phenomena in which they may be involved and affected by all the conditions and by all the intermediate species peculiar to the electric discharge. 

For the most part, the ultimate objective of this research is the production of new and useful products or the production of known products at less cost. Thus, the essential background of information already developed by the physicist, electrochemist, chemical and electrical engineer must be brought together in a manner that is readily understood by each. The papers presented in this volume reflect this diversity of interest in discharge chemistry. 

FIGURE 279. Illustration of a late-nineteenth-century ozone generator. The apparatus was designed to expose flowing oxygen gas to a silent discharge of electricity since sparks decompose ozone (1 mol O3) back to oxygen (1.5 mol O2). (From Roscoe and Schorlemmer, A Treatise on Chemistry, 1894 )... 

Used (particularly He, Ar) to provide an inert atmosphere, e.g. for welding, and in electric light bulbs, valves and discharge tubes (particularly Ne). Liquid He is used in cryoscopy. The amounts of He and Ar formed in minerals by radioactive decay can be used to determine the age of the specimen. Xe and to a lesser extent Kr and Rn have a chemistry the other noble gases do not form chemical compounds. 

MoTaggart F K 1967 Plasma Chemistry in Electrical Discharges (Amsterdam Elsevier)... 

It is significant that the earliest records of life on Earth start shortly after the period of impact frustration. Apparently life formed as soon as the conditions permitted it. Life originated from compounds produced by prebiotic organic chemistry. The source of the molecules included those produced on Earth by energetic processes such as impacts and electrical discharges as well as those that fell in from space. Whatever processes occurred, they would have had to happen either in the deep ocean or in what might have been rare regions of land and shallow water. 

This definition of electrochemistry disregards systems in which nonequilibrium charged species are produced by external action in insulators for example, by electric discharge in the gas phase (electrochemistry of gases) or upon irradiation of liquid and sohd dielectrics (radiation chemistry). At the same time, electrochemistry deals with certain problems often associated with other fields of science, such as the structure and properties of sohd electrolytes and the kinetics of ioific reactions in solutions. 

This section treats the plasma physics and plasma chemistry of the typical silane-hydrogen RF discharge, with occasional examples that employ a somewhat higher excitation frequency. Electrical characterization of the discharge is followed by an analysis of the silane chemistry. An appropriate set of gas phase species is presented, which are then used in the modeling of the plasma. A comparison is made between modeling results and experimental work in ASTER. Extension to 2D modeling is presented as well. 

The difference in the ionization potentials of xenon and krypton (1170 versus 1351 kj/mol) indicates that krypton should be the less the reactive of the two. Some indication of the difference can be seen from the bond energies, which are 133 kj/mol for the Xe-F bond but only 50 kj/mol for the Kr-F bond. As a result, XeF2 is considerably more stable of the difluorides, and KrF2 is much more reactive. Krypton difluoride has been prepared from the elements, but only at low temperature using electric discharge. When irradiated with ultraviolet light, a mixture of liquid krypton and fluorine reacts to produce KF2. As expected, radon difluoride can be obtained, but because all isotopes of radon undergo rapid decay, there is not much interest in the compound. In this survey of noble gas chemistry, the... 

Chemical Reactions in Electrical Discharges," Blaustein, B. C., Ed. American Chemical Society, Advances in Chemistry Series No. 80, 1969. 

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