Oxygen origin

Is this the oxygen originally present in benzoic acid, or is it the oxygen of methanol ... 

Here, the 21% of oxygen originally present in air has reacted on a 1 1 volume basis with carbon to produce one volume of carbon dioxide. The nitrogen content of the air does not take part in the reaction process. 

In natural water, singlet oxygen originating from humic substances has been shown, for example, to oxidize thioether pesticide contaminants such as disulfoton (Zepp et al. 1981). Irradiation of dilute hydrogen peroxide in the presence of various non-sunlight-absorbing herbicides results in enhanced oxidation of these substances (Draper and Crosby 1981). 

A redox mechanism involving lattice oxygen originally proposed in 1954 by Mars and Van Krevelen (22) for hydrocarbon oxidation over V2O5 can be applied to a variety of catalytic oxidation reactions (23). The following illustrates a lattice redox mechanism for CO oxidation ... 

Thereby, the concentration of the electron holes in the boundary layer of CU2O will be decreased. The chemisorption of H2O destroys the inundation boundary layer of CU2O, produced by the preceding chemisorption of oxygen originally present after contact with air... 

The oxyhydration of propene to acetone occurs at a much lower temperature than the allylic oxidation and demands, in principle, the presence of excess steam. The reaction is initiated by addition of a proton from the catalyst surface and the acetone formation involves oxygen originating from water. 

There remains an area where progress is still to be made. This is in the invention of new, inexpensive, and temperature-variable initiators. The present reliance on azoiso-butyronitrile (AlBN) and dibenzoyl peroxide limits the temperature range, and there is always some danger with peroxides. The use of triethylborane and oxygen, originally introduced by Brown some decades ago, has recently been appreciated better because it permits radical initiation at low temperatures. 

Under the initially neutral conditions of hydrogenation, the production of the phenylpropanols as the major products represents a stabilized form of the initially released units. Loss of oxygen from the a- and impositions by a hydrogenolysis reaction may well have occurred. The results of the studies, using initially alkaline conditions whereby phenyl-ethanoid products result, help support the belief that alkali facilitates the 0-7 carbon-carbon cleavage and that oxygen originally was associated with the 0-carbon atom. 

Multiple bonds to an element count as multiple single bonds to that element. That is, the carbon-oxygen double bond of carbonyl group (C=0) is oxidatively equivalent to a carbon atom with two single bonds to oxygen originating from it (-O-C-O-). 

In conventional crude oil, these other atoms (nitrogen, oxygen, and metals) may be of little consequence. Heavy oil contains substantial amounts of these atoms, and the nature of the distillation process dictates that virtually all of the metals and substantial amounts of the nitrogen and oxygen originally present in the petroleum will be concentrated in the residua. 

During ATP synthesis from ADP and phosphate (at neutral pH or above), one hydroxyl ion is released per ATP molecule synthesized. That oxygen originates from... 

A mechanism for catalytic dehydrogenation was proposed to explain these observations. The researchers used deuterium-labeled formic acid to discriminate against background water and hydrogen. In the scheme below. Os represents surface lattice oxygen, while oxygen originating from formic acid is... 

Can we identify the strongly bonded oxygen state as the backspillover oxygen originating from the solid electrolyte Since the strongly bonded state is... 

Most of the oxygen originally fed to the ozonizer was recovered and recycled, as shown above, but some of it, about 0.4 pound of oxygen per pound of useful ozone recovered in the new carrier gas, was lost. Total oxygen consumption to produce each pound of usable ozone was therefore about 1.4 pounds of oxygen. 

---