The Reaction of Hydrogen and Oxygen in the Presence of Silver. The Third Explosion Limit

1941 ◽  
Vol 9 (1) ◽  
pp. 120-120 ◽  
Author(s):  
Harold R. Heiple ◽  
Bernard Lewis
Keyword(s):  
The Third ◽  
Explosion Limit

Rates of elementary processes in the chain reaction between hydrogen and oxygen II. Kinetics of the reaction of hydrogen atoms with molecular oxygen

1963 ◽  
Vol 275 (1363) ◽  
pp. 559-574 ◽  
Keyword(s):  
Molecular Oxygen ◽  
Kinetic Studies ◽  
Negative Temperature ◽  
Product Analysis ◽  
Hydrogen Atoms ◽  
The Third ◽  
Rate Determining Step ◽  
A Value ◽  
Explosion Limit ◽  
Kinetics Of

The addition of molecular oxygen was found to increase the rate of rem oval of hydrogen atoms in a flow system at and below room temperature. Kinetic studies of this process using argon carrier showed that the rate-determining step is the third-order reaction H + O2 + Ar = HO 2 + Ar. (2) Atomic oxygen in small concentrations is produced in the system. Product analysis and measurements of oxygen atom concentrations indicated that the principal reactions removing HO 2 under these conditions are H+HO 2 = H 2 +O 2 , (12a) H+HO 2 = OH+OH, (12b) H+HO 2 = H 2 O+O 2 , (12c) A value for k 2 of 2.2 x 10 -32 cm 6 molecule -2 s -1 was determined at 293 °K. Reaction (2) was found to have a small negative temperature coefficient. These data and values of k 2 from explosion limit studies can be represented by the expression k 2 = 1.3 x 10 -33 exp (+ 1600 + 700/ RT ) cm 6 molecule -2 s -1 in the range 250 to 800 °K. The third-body efficiencies in reaction (2) at 293 °K of He and H 2 O relative to Ar are similar to those obtained from data on the second explosion limit at higher temperatures.

scholarly journals The mechanism of the hydrogen-oxygen reaction I. The third explosion limit

1946 ◽  
Vol 185 (1003) ◽  
pp. 353-369 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Potassium Chloride ◽  
Fair Agreement ◽  
The Other ◽  
Satisfactory Description ◽  
The Third ◽  
Explosion Limits ◽  
Explosion Limit ◽  
Oxygen Reaction

One of the outstanding facts about the hydrogen-oxygen reaction is the existence of three distinct Explosion limits, designated, in order of increasing pressure, the first, second and third explosion limits. The influence on the third limit of ( a ) hydrogen-oxygen proportions, ( b ) additions of nitrogen, carbon dioxide and steam, has been examined: the measurements were made mainly at 586° in a silica vessel coated with potassium chloride (which controls the reaction chains). The results are qualitatively consistent with the theory that the third limit depends upon the (essentially isothermal) branching of reaction chains. An expression based upon the equations OH + H 2 = H 2 O + H, H + O 2 = OH + O, O + H 2 = OH + H, H + O 2 + M = HO 2 + M , HO 2 + H 2 =H 2 O + OH, together with the assumption that HO 2 diffuses to the walls of the vessel and is destroyed, leads to a satisfactory description of the third limit as well as of the other two. The constants characteristic of the various gases participating are in fair agreement with those derived by independent means.

scholarly journals The chemistry involved in the third explosion limit of H2–O2 mixtures

2014 ◽  
Vol 161 (1) ◽  
pp. 111-117 ◽  
Author(s):  
Antonio L. Sánchez ◽  
Eduardo Fernández-Tarrazo ◽  
Forman A. Williams
Keyword(s):  
The Third ◽  
Explosion Limit

A MASS SPECTROMETRIC STUDY OF THE OXIDATION OF HYDROGEN SULPHIDE PART I. OBSERVATION AND IDENTIFICATION OF SOME INTERMEDIATES

1963 ◽  
Vol 41 (10) ◽  
pp. 2607-2620 ◽  
Author(s):  
D. G. H. Marsden
Keyword(s):  
Hydrogen Sulphide ◽  
Intermediate Formation ◽  
Mass Spectrometric Study ◽  
Reaction Vessel ◽  
Spectrometric Study ◽  
The Third ◽  
Small Leak ◽  
Direct Sampling ◽  
Oxidation Of Hydrogen ◽  
Explosion Limit

The oxidation of hydrogen sulphide has been followed mass-spectrometrically by direct sampling from a reaction vessel having a small leak. In the neighborhood of the third explosion limit, there is a period of 8–12 seconds of accelerating reaction before the explosion; during this time peaks are observed to grow, disappearing after explosion. By using D2S/16O2 and H2S/18O2 mixtures, it has been shown that these peaks arise from the ions H2+, S2O+, H2SO+, S2+, and H2S2+. It is evident that the first two ions represent the intermediate formation of hydrogen and disulphur monoxide; the parents of the last three ions are discussed, and it is concluded that the most likely possibilities are H2SO2, S2, and H2S2. Only during the explosion itself is there any evidence for SO radical.

H2/Air Autoignition Dynamics around the Third Explosion Limit

2019 ◽  
Vol 145 (1) ◽  
pp. 04018074 ◽  
Author(s):  
Efstathios-Al. Tingas ◽  
Dimitrios C. Kyritsis ◽  
Dimitris A. Goussis
Keyword(s):  
The Third ◽  
Explosion Limit

The mechanism of the hydrogen-oxygen reaction II. The reaction occurring between the second and third explosion limits

1946 ◽  
Vol 185 (1003) ◽  
pp. 369-376 ◽  
Keyword(s):  
Preceding Paper ◽  
Experimental Results ◽  
New Method ◽  
Chain Mechanism ◽  
Experimental Conditions ◽  
The Third ◽  
Rate Expression ◽  
Explosion Limits ◽  
Explosion Limit

The equation for the rate of combination of hydrogen and oxygen, based upon the most probable chain mechanism, is very complicated and difficult to apply, without drastic approximations, to the experimental results. A new method of approach is here employed: the equation is factorized by considering first the condition for the third explosion limit (preceding paper) which allows the determination of most of the constants. With the help of these results the rate expression can be tested^ and the form of the function describing the initiating reaction examined. It is concluded that, under the experimental conditions, the chains are probably initiated by the dissociation of hydrogen: H 2 + M = 2H.

Progress report on 21-cm observations at low latitude between longitudes (l 11) 0° and 66°

1967 ◽  
Vol 31 ◽  
pp. 177-179
Author(s):  
W. W. Shane
Keyword(s):  
Preliminary Report ◽  
Progress Report ◽  
Galactic Centre ◽  
Low Latitude ◽  
The Third ◽  
Introductory Lecture ◽  
Centre Region

In the course of several 21-cm observing programmes being carried out by the Leiden Observatory with the 25-meter telescope at Dwingeloo, a fairly complete, though inhomogeneous, survey of the regionl11= 0° to 66° at low galactic latitudes is becoming available. The essential data on this survey are presented in Table 1. Oort (1967) has given a preliminary report on the first and third investigations. The third is discussed briefly by Kerr in his introductory lecture on the galactic centre region (Paper 42). Burton (1966) has published provisional results of the fifth investigation, and I have discussed the sixth in Paper 19. All of the observations listed in the table have been completed, but we plan to extend investigation 3 to a much finer grid of positions.

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