Nitrogen other than nitric oxide

Response to Oxides of Nitrogen Other than Nitric Oxide. Although NO is normally the oxide of nitrogen in combustion products, exhaust aging at ambient temperature forms other products such as N02, N204, N205, and HN03. Catalytic muffler treatment of exhaust may produce... 

From the thermodynamic data of Appendix C, show that the product of the reaction of ammonia gas with oxygen would be nitrogen, rather than nitric oxide, under standard conditions and in the absence of kinetic control by, for example, specific catalysis of NO formation by platinum. (Assume the other product to be water vapor.)... 

Detection of compounds other than nitric oxide requires conversion of the analytes (either directly or indirectly) into nitric oxide. The so-called NO, box that is frequently used in atmospheric field studies to determine both NO and NO2, requires measurement with and without conversion of NO2 to NO by photolysis. Similarly, the total reactive oxides of nitrogen can be converted to NO by passing the... 

One per cent potassium iodide in neutral buffered or alkali solutions is more stable and useful than 20% potassium iodide in bubblers for collection and determination of ozone in air. Either 1 % solution may be used to determine low concentrations of ozone however, there is a difference in their stoichiometry. Over the range of 0.01 to 30 p.p.m. (v./v.) results by the alkaline procedure should be multiplied by 1.54 to correct for stoichiometry. The neutral reagent does not require acidification and has more nearly uniform stoichiometry. The alkaline procedure is preferable when final analysis may be delayed. Experiments with boric acid for acidification of samples in the alkaline reagent show that some mechanism other than oxidation of iodide to iodate or periodate is involved, possibly formation of hypoiodite. Preliminary experiments with gas phase titrations of nitrogen dioxide and nitric oxide against ozone confirm the stoichiometry of the neutral reagent as 1 mole of iodine released for each mole of ozone. 

Mixed potentials have been found to be important in reaction systems other than CO oxidation. Michaels and co-workers studied a platinum electrode exposed to nitric oxide, nitrogen dioxide and oxygen in the region of 600-800°C. Using e.m.f. data and closed-circuit work at low overpotentials (to avoid modifying coverages of electroactive species) it was shown that two charge-transfer reactions were important. 

In the measurement of nitrqgen dioxide with this technique, it is thermochemically converted to nitric oxide by reaction with molybdenum at about 200 C. The extent of possible interferences at various monitoring sites from nitrogen compounds other than amhionia, which does not interfere unless the temperature is considerably higher than 2(X) C, remains to be assessed. The instrumentation of this procedure is inherently more reliable than the original colorimetric analyzers. Unfortunately, the mutual equivalence in monitoring situations of data obtained by these two techniques has not yet been evaluated. This is particularly important for the data from California, where the colorimetric method has been used for more than 20 yr. 

This contributes to the propensity of nitric oxide in dilute solutions to principally form nitrite rather than an equamolar amount of nitrite and nitrate as predicted by Reaction 22 (Ignarro, 1990 Ignarro et ai, 1993). In a biological system, nitrogen dioxide may also directly extract an electron from lipids or other compounds to form nitrite directly (Pryor and Lightsey, 1981). 

Lewis hi his It tG paper and in his book on valence emphasized the fact that there exist only a few stable molecules and complex ions (other than those containing atoms of the transition elements) for which the total number of electrons is odd. He pointed out that in general an odd molecule, such as nitric oxide or nitrogen dioxide, would be expected to use its unpaired electron to form a bond with another such molecule, and that the monomeric substance should accordingly be very much less stable than its dimer and he stated that the method by winch the unpaired electron is firmly held in the stable odd molecule v/as not at that time understood. Since then the explanation of the phenomenon has been found, as the result of the... 

There is a remarkable fact about the reaction between nitric oxide and stannous chloride. At a temp, of fully 100°, there is no action between nitric oxide and acid stannous chloride soln. The stannous chloride remains unchanged for hours together, and neither nitrogen nor hydroxylamine is formed. The only thing we have noticed is always a trace of ammonia in experiments at 100°, and this, we are inclined to believe, is due to some other cause than this reaction alone. At 90°, the action is still exceedingly small, but as the temp, descends from about 80°, it becomes rapidly greater with the descent. 

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