Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Oxygen chemistry evolution

The surface of activated alumina is a complex mixture of aluminum, oxygen, and hydroxyl ions which combine in specific ways to produce both acid and base sites. These sites are the cause of surface activity and so are important in adsorption, chromatographic, and catalytic appHcations. Models have been developed to help explain the evolution of these sites on activation (19). Other ions present on the surface can alter the surface chemistry and this approach is commonly used to manipulate properties for various appHcations. [Pg.155]

The corrosion of tin by nitric acid and its inhibition by n-alkylamines has been reportedThe action of perchloric acid on tin has been studied " and sulphuric acid corrosion inhibition by aniline, pyridine and their derivatives as well as sulphones, sulphoxides and sulphides described. Attack of tin by oxalic, citric and tartaric acids was found to be under the anodic control of the Sn salts in solution in oxygen free conditions . In a study of tin contaminated by up to 1200 ppm Sb, it was demonstrated that the modified surface chemistry catalysed the hydrogen evolution reaction in deaerated citric acid solution. [Pg.809]

Colorless, reactive gas. Oxygen was not present in the initial atmosphere of the Earth, although at 50 % it is the most common element in the crust of the Earth (oxides, silicates, carbonates, etc.). The compound with hydrogen is remarkable. The hydrides of all other elements are unpleasant compounds, but H20 is the molecule of life. The 02 found in the air today, of which it makes up 20 %, was formed in the process of evolution by photosynthesis of algae, which then also allowed life on solid land. Oxidation with oxygen became and is still the dominant pathway of life forms for obtaining energy (respiration). Used in medicine in critical situations. Oxidations play a key role in chemistry (sulfuric acid, nitric acid, acetic acid, ethylene oxide, etc.). The ozone layer in space protects the Earth from cosmic UV radiation. Ozone (03) is used in the... [Pg.35]

Thus, the ability of the holes and electrons to bring about redox chemistry can be controlled by changes in pH which ensure that the CB and VB straddle the hydrogen and oxygen evolution potentials. [Pg.206]

Walker RJ, Hanson GN, Papike JJ, O Neil JR, Laul JC (1986) Internal evolution of the Tin Mountain pegmatite, Black Hills, South Dakota. Am Min 71 440-459 Wenger M and Armbruster T (1991) Crystal chemistry of lithium oxygen coordination and bonding. Eur J Mineral 3 387-399... [Pg.195]

Burke, L. D. Oxide growth and oxygen evolution on noble metals. In Studies in physical and theoretical chemistry. 11. Electrodes of conductive metal oxides, part A, ed. S. Trasatti, 141. Amsterdam Elsevier, 1980. [Pg.97]

Dimesityldioxirane, a crystalline derivative, has been isolated by Sander and colleagues and subjected to X-ray analysis. The microwave and X-ray data both suggest that dioxiranes have an atypically long 0—0 bond in excess of 1.5 A. Those factors that determine the stability of dioxiranes are not yet completely understood but what is known today will be addressed in this review. A series of achiral, and more recently chiral oxygen atom transfer reagents, have been adapted to very selective applications in the preparation of complex epoxides and related products of oxidation. A detailed history and survey of the rather remarkable evolution of dioxirane chemistry and their numerous synthetic applications is presented in Chapter 14 of this volume by Adam and Cong-Gui Zhao. Our objective in this part of the review is to first provide a detailed theoretical description of the electronic nature of dioxiranes and then to describe the nuances of the mechanism of oxygen atom transfer to a variety of nucleophilic substrates. [Pg.26]


See other pages where Oxygen chemistry evolution is mentioned: [Pg.292]    [Pg.149]    [Pg.426]    [Pg.384]    [Pg.385]    [Pg.37]    [Pg.62]    [Pg.1294]    [Pg.336]    [Pg.2]    [Pg.32]    [Pg.55]    [Pg.71]    [Pg.171]    [Pg.193]    [Pg.217]    [Pg.240]    [Pg.251]    [Pg.253]    [Pg.278]    [Pg.280]    [Pg.292]    [Pg.307]    [Pg.311]    [Pg.333]    [Pg.420]    [Pg.429]    [Pg.430]    [Pg.450]    [Pg.43]    [Pg.151]    [Pg.278]    [Pg.34]    [Pg.8]    [Pg.212]    [Pg.62]    [Pg.1]    [Pg.278]    [Pg.193]    [Pg.36]    [Pg.522]    [Pg.477]   
See also in sourсe #XX -- [ Pg.9 , Pg.10 ]




SEARCH



Oxygen chemistry

© 2024 chempedia.info