Photosensitized Chain Reactions in Alkaline Solutions of Nitrous Oxide in 2-Propanol

1967 ◽  
Vol 89 (6) ◽  
pp. 1302-1307 ◽  
Author(s):  
Warren V. Sherman
Keyword(s):  
Nitrous Oxide ◽  
Alkaline Solutions ◽  
Chain Reactions

Radiation sensitized chain reactions. Aqueous nitrous oxide and methanol

1978 ◽  
Vol 82 (1) ◽  
pp. 26-29 ◽  
Author(s):  
T. G. Ryan ◽  
T. E. M. Sambrook ◽  
G. R. Freeman
Keyword(s):  
Nitrous Oxide ◽  
Chain Reactions

The thermal decomposition of nitrous oxide I. Secondary catalytic and surface effects

1955 ◽  
Vol 231 (1185) ◽  
pp. 162-178 ◽  
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Nitrous Oxide ◽  
Surface Reaction ◽  
Order Rate Constant ◽  
Side Reactions ◽  
Chain Reactions ◽  
First Order ◽  
Reaction Vessels ◽  
Decomposition Of Nitrous Oxide

In the region of pressure 0 to 500 mrn approximately to the equation the thermal decomposition of nitrous oxide conforms approximately to the equation k = an /1 + a'n + bn , where k is the form al first-order rate constant, — (1/n) d n /d t , n the initial concentration and a, a' and b are nearly constant. Above about 100 m m this expression approximates to k = A + bn , which holds up to several atmospheres. Fresh and more detailed experiments have once again disproved the suggestion that the first term in these expressions is due to a surface reaction. (In certain states of reaction vessels, made of a particular brand of silica, a surface reaction may appear but is immediately recognizable by special criteria, and can be eliminated.) Detailed study of the formation of nitric oxide in the course of the decomposition, and of the effect of inert gas upon this process, shows that side reactions involving oxygen atoms, chain reactions and catalysis by nitric oxide play only minor parts in determining the shape of the k-n curve. The form of this curve, which is an inherent character of the reaction N 2 O = N 2 + O, raises theoretical questions of considerable interest.

Radical and molecular yields in the radiolysis of aqueous solution IV. Nitrous oxide solutions containing hexachloro-anions of iridium and platinum

1967 ◽  
Vol 298 (1454) ◽  
pp. 239-254 ◽  
Keyword(s):  
Aqueous Solution ◽  
Nitrous Oxide ◽  
Alkaline Solution ◽  
Solute Concentration ◽  
Alkaline Solutions ◽  
Electron Yield

From competition studies on γ -irradiated solutions containing Ir(III), Ir(IV) or Pt(II) and N 2 O, G e - aq+ was found to be 3.10 ± 0.10 at natural pH. In confirmation of previous measurements the electron yield increased in alkaline solution. Measurements of molecular yields in the iridium system indicate that at zero solute concentration at natural pH, G 0 H 2 = 0.44 ± 0.02 and G 0 H 2 O 2 = 0.78 ± 0.05. In alkaline solutions both Pt(IV) and Ir(III) are thermally and photochemically labile. From competition studies at natural pH k ( e - + Ir(III)) = 7.4 x 10 9 M -1 s -1 and k ( e - + Ir(IV)) = 2.6 x 10 10 M -1 s -1 and at pH 13 k ( e - + Ir(III)) = 1.0 x 10 10 M -1 s -1 and from pulsing experiments k ( e - + Pt(II)) = 6.7 x 10 9 M -1 s -1 and k ( e - + Pt(IV)) = 3.6 x 10 10 M -1 s -1 .

scholarly journals The kinetics of the reaction between hydrogen and nitrous oxide.─I

1933 ◽  
Vol 142 (847) ◽  
pp. 524-545 ◽  
Keyword(s):  
Nitrous Oxide ◽  
Kinetic Method ◽  
Gaseous Mixture ◽  
Theoretical Treatment ◽  
Chain Process ◽  
Combustion Chemistry ◽  
Chain Reactions ◽  
Simple Molecules ◽  
A Chain ◽  
Kinetics Of

Until about five years ago, the theoretical treatment of the mechanism of the oxidation of simple molecules had been comparatively neglected. Prior to this, however, considerable progress had been made in the study of the kinetics of thermal and photochemical gas reactions. That knowledge has now been successfully applied and extended to solve some of the major problems in combustion chemistry, and thereby has given rise to the development of the theory of thermal chain reactions. Hitherto, the investigation of these reactions has been confined almost entirely to oxidations by molecular oxygen. It is known, however, that many gases ignite in:nitrous oxide at about the same temperature as they do in oxygen, and it might be anticipated that here, too, a chain process is in operation. The object of studying the interaction of hydrogen and nitrous oxide was to determine whether it is a chain reaction, and if so, to make a detailed analysis of its mechanism by the kinetic method. One of the first criteria in looking for the possibility of the propagation of chains in a gaseous mixture is that the reaction must be exothermic. This condition is amply fulfilled in the present instance, for 75 k. cal. are liberated per mole of water formed. Indeed, the reaction is even more exothermic than the formation of one mole of water from hydrogen and oxygen, when only 50 k. cal. are evolved. This greater exothermicity is due to the fact that 45 k. cal. required to dissociate 1 mole of N 2 O N 2 and O, whereas the production of 1 mole of O atoms from O 2 required about 60 k. cal.

scholarly journals Methylperoxyl Radicals: A Study of the γ-Radiolysis of Methane in Oxygenated Aqueous Solutions

1984 ◽  
Vol 39 (2) ◽  
pp. 217-221 ◽  
Author(s):  
Heinz-Peter Schuchmann ◽  
Clemens von Sonntag
Keyword(s):  
Hydrogen Peroxide ◽  
Nitrous Oxide ◽  
Formic Acid ◽  
Aqueous Solutions ◽  
Phosphate Buffer ◽  
Alkaline Solutions ◽  
Acid Yield ◽  
Hydroxymethyl Radicals ◽  
Product Study

A product study has been made of the γ-radiolysis of aqueous methane solutions that also contained nitrous oxide and oxygen. Formaldehyde (G = 2.8), hydrogen peroxide (G = 2.1), methanol (G = 1.5), methylhydroperoxide (G = 0.8), formic acid (G = 0.3), and dimethylperoxide (G = 0.1) were found. In alkaline solutions (pH 8, 10-3 M phosphate buffer), the formaldehyde yield rises to G = 3.2, while the formic acid yield falls to almost zero (G = 0.05). The initial precursor of the carbon-containing products is the methylperoxyl radical. The methylperoxyl radicals decay through a short-lived tetroxide along various pathways. The most prominent one leads to formaldehyde, methanol and oxygen. Methoxyl radicals (and oxygen) are also formed and, after rearrangement into hydroxymethyl radicals and their conversion into hydroxymethylperoxyl radicals, eventually yield formic acid and probably further formaldehyde. A route to formaldehyd and hydrogen peroxide is also envisaged. Methylhydroperoxide is formed in the reaction of methylperoxyl radicals with HO2 /O2·̄ radicals (from radiolytic H atoms and the unimolecular decay of the hydroxymethylperoxyl radical)

Radiation sensitized chain reactions. Aqueous nitrous oxide and 2-propanol

1977 ◽  
Vol 81 (15) ◽  
pp. 1455-1458 ◽  
Author(s):  
T. G. Ryan ◽  
G. R. Freeman
Keyword(s):  
Nitrous Oxide ◽  
Chain Reactions

Radical and molecular yields in the γ -radiolysis of water. III. The nitrous oxide-sodium tellurite system

1965 ◽  
Vol 287 (1411) ◽  
pp. 444-456 ◽  
Keyword(s):  
Nitrous Oxide ◽  
Solute Concentration ◽  
Alkaline Solutions ◽  
Alkaline Ph ◽  
Dissolved Gas ◽  
Solvated Electrons ◽  
Sodium Tellurite ◽  
Predominant Form ◽  
Different Doses

G (H 2 ), G (O 2 ), G (N 2 ), G (H 2 O 2 ) and G (Te VI ) have been measured at different doses for 60 Co γ -irradiated aqueous alkaline (pH > 10.4) solutions of sodium tellurite containing either oxygen or nitrous oxide or no dissolved gas. Where possible, material balances were obtained and G (H 2 ) = 0.40 was independent of dose, solute concentration and pH and is believed equal to G H 2 . Reasons are given for considering that G H 2 O 2 = 0.60 in these systems. Tellurite ions react with solvated electrons and k ( µ = 0.24) = 5.8 × 10 8 M -1 s -1 . The ratio k ( e - aq. + Te IV )/ k ( e - aq. + N 2 O) varies from 0.10 at pH 12.6 to 0.53 at pH 14.0 suggesting that the predominant form of tellurite ion is TeO 2- 3 . These and other data indicate that an increase of pH in the range 11 to 14 causes each of the yields of reducing and oxidizing radicals to increase by one unit but those of H 2 and H 2 O 2 are unchanged. G (Te VI ) for oxygenated tellurite solutions is dependent on both oxygen concentration and dose which precludes the use of this system as a reliable method for determination of radical yields in aqueous alkaline solutions.

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