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Oxygen ozone formation from

Washida, N., Y. Mori, and I. Tanaka. Quantum yield of ozone formation from photolysis of the oxygen molecule at 1849 and 1931 A. J. Chem. Phys. 54 1119-1122, 1971. [Pg.672]

From thermochemical considerations only, light of wavelength less than 8420 A. could possibly bring about ozone formation from oxygen. However, of the probable mechanisms, the one requiring the least energy is... [Pg.48]

It is now known that these basic assumptions are incorrect. Thiemens and Heidenreich (1983) demonstrated that, in the process of ozone formation from molecular oxygen, ozone is equally enriched in and or This has... [Pg.2073]

The effects of various added gases on the rate of formation of ozone in a flow system have been studied at 1849 A. with light from a mercury-rare gas low pressure discharge (92). In a 30-mm. diameter cylindrical quartz reaction vessel at a flow rate of 2.0 l./min. at 1-atm. total pressure and 0.25-atm. oxygen pressure, the relative rates of ozone formation were ... [Pg.49]

Wilkinson and Mulliken (105) have pointed out that a direct transition from 32ff to 3IIU is allowed, and have obtained evidence for a weak continuum attributable to 3nu - 32s. They suggested that this may be more important in the decomposition of oxygen above 1750 A. than predissociation of 32u. If this were the case, the quantum yield of ozone formation would have to be quite small at 1849 A. since most of the light would still be absorbed in the transition 32 32 . Although quan-... [Pg.51]

Of the above reactions, only (15) is consistent with the experimental observations. Calculations from collision theory based on the endother-micity of reaction (13) indicate that only one collision in about 104 could yield oxygen atoms. Since the quantum yield of ozone formation has been estimated at 0.03 (91) and as high as 0.14 (18), and since long chains are not possible, this reaction cannot be important. In reaction (14) one mercury atom is removed for each oxygen atom formed. Since 60 or more ozone molecules may be formed for each mercury atom removed, this reaction cannot be important unless mercury is regenerated. The postulated reaction (61)... [Pg.53]

Chemical Properties.—Ozone is an endothermic substance, its formation from gaseous oxygen being attended by a large absorption of heat, namely 34,500 calories per gram molecule at constant volume.8 Thus... [Pg.146]

Kimura el al. (2007) reported the first reproducible production of mass-independent oxygen in iron and silicate smokes from gas-phase reactions (Fig. 4.8). It is possible to misinterpret these data as being associated with ozone, which is known to have a large mass-independent composition. Comparing kinetics of the rates of the two reaction channels competing for reaction with O-atoms O + O2 + M — O3 + M and O + H2 — OH + H, one finds a factor of twenty higher probability for a H2 sink compared to ozone formation. [Pg.119]

Scheme 1.2 Mechanism of the ozone formation in the stratosphere [26]. Dioxygen is photochemically split into atomic oxygen, which adds to another dioxygen molecule. The excess energy from the recombination is carried away by a collision partner (M). Scheme 1.2 Mechanism of the ozone formation in the stratosphere [26]. Dioxygen is photochemically split into atomic oxygen, which adds to another dioxygen molecule. The excess energy from the recombination is carried away by a collision partner (M).

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