Steady-state intermediate concentrations and rate constants. HO2 results

Westenberg, A. A.; deHaas, N.

doi:10.1021/j100655a018

Cited by 62 publications

(32 citation statements)

References 2 publications

(3 reference statements)

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“…At contact times of 0.005 to 0.01 sec, the aldehyde is completely burned and the concentration of all the reaction products increases. The amount of C02 formed by reaction (10) as before is one order of magnitude higher than that formed by reaction (9). Almost all the aldehyde is transformed to carbon dioxide.…”

Section: Discussionmentioning

confidence: 82%

The rate constant of the reaction HO₂ + COCO₂ + OH

Vardanyan¹,

Sachyan²,

Nalbandyan³

1975

Int J of Chemical Kinetics

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The high-temperature oxidation of formaldehyde in the presence of carbon monoxide was investigated to determine the rate constant of the reaction HOZ + CO = CO:! + OH (10). In the temperature range of 878-952°K from the initial parts of the kinetic curves of the HOz radicals and CO, accumulation at small extents of the reaction, when the quantity of the reacted formaldehyde does not exceed lo%, it was determined that the rate constant klo isA computer program was used to solve the system of differential equations which correspond to the high-temperature oxidation of formaldehyde in the presence of carbon monoxide. The computation confirmed the experimental results. Also discussed are existing experimental data related to the reaction of HOt with CO.On the basis of our detailed knowledge of the mechanism of the oxidation of formaldehyde in a reactor treated with boric acid, it was possible to attempt to determine the rate constant of the elementary reaction HO2 + CO=CO2 + O H I n the reaction mixture, which contained 1% formaldehyde and 99% air, part of the nitrogen was replaced by carbon monoxide. The mechanism of the oxidation of formaldehyde in the presence of carbon monoxide may be represented by the following reactions (Table I). The units of the rate constants are given in sec-', cm3/molec.sec, and cm6/molec2.sec for the reactions of the first, second, and third orders, respectively.Reactions (1 1)- (22) have been included because reaction (9) generates H atoms. The reaction O H + HO2 = H2O + 0 2 has not been included in the scheme because its velocity is noticeably less than the velocities of reactions (5) and (8). It follows from this scheme that the rate of formation of carbon dioxide is equal to d(C02)/dt = k9(0H)(CO) + klo(HOz)(CO). To evaluate the contribution of reaction (9)

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Section: Discussionmentioning

confidence: 82%

The rate constant of the reaction HO₂ + COCO₂ + OH

Vardanyan¹,

Sachyan²,

Nalbandyan³

1975

Int J of Chemical Kinetics

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“…If so, this would have resulted in a measured rate constant which was smaller than the true rate constant. (The 0 atoms in reaction (14) would have been formed from the vacuum ultraviolet flash photolysis of 0 2 ; the OH from reactions (6), (8), and/or (9).) This possibility can be discounted for the same reason as given above for reactions (4)-(9).…”

Section: Resultsmentioning

confidence: 99%

A flash photolysis‐resonance fluorescence study of the reaction of atomic hydrogen with molecular oxygen H + O₂ + M → HO₂ + M

Wong

Davis

1974

Int J of Chemical Kinetics

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Using the technique of flash photolysis-resonance fluorescence, absolute rate constants have been measured for the reaction H + 0 2 + M 4 HOz + M over a temperature range of 220-360°K. Over this temperature range, the data could be fit to an Arrhenius expression of the following form:The units for kAr are cm6/mole-s. At 300°K the relative efficiencies for the third-body gases Ar:He:H2:N2:CH4 were found to be 1.0:0.93:3.0:2.8:22.Wide variations in the photoflash intensity at several temperatures demonstrated that the reported rate constants were measured in the absence of other complex chemical processes.

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“…A similar con clusion regarding the dominance of the two abstraction paths at � 11000K was also reached from a very detailed study of a complex H2-02-N2 flame (70), but the 0 abstraction yielding OH + OH was considered to be several times the more likely of the two. Taken in conjunction with the room tempera ture result (27) this would imply an appreciably greater activation energy for the OH + OH path than for Hz + O2, which may be pertinent to the matter discussed below. The substitution path H20 + 0 was found to be more likely than either abstraction in an earlier investigation (71 (78).…”

Section: H02 Radical Reactionsmentioning

confidence: 92%

“…The distribution of the three possible paths for the H + H02 reaction, i.e. H2 + O2, OH + OH, or H20 + 0, received attention (27). With H02 generated from H + O2 + M in a fast flow system, the steady state concen trations of OH and 0 can be related in a straightforward way to the H decay rate and the above reaction rate distribution.…”

Section: H02 Radical Reactionsmentioning

confidence: 99%

“…(e) There is possibly some serious question about the room temperature rate of CO + H02 ->-CO2 + OH. Most of the evidence (74)(75)(76)(77) indicates the reaction to be negligibly slow, but one fairly direct experiment (27) on the measurement of the rate constant relative ,to H + H02 --+ OH + OH implies (assuming the latter to be very fast) that it may be medium fast. (f) Major disagreements exist for the important atmos pheric reactions 0(1D) + 03 -?…”

Section: A Problem Status Summarymentioning

confidence: 99%

See 1 more Smart Citation

Gas Phase Reaction Kinetics

Westenberg¹

1973

Annu. Rev. Phys. Chem.

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Steady-state intermediate concentrations and rate constants. HO2 results

Cited by 62 publications

References 2 publications

The rate constant of the reaction HO₂ + COCO₂ + OH

The rate constant of the reaction HO₂ + COCO₂ + OH

A flash photolysis‐resonance fluorescence study of the reaction of atomic hydrogen with molecular oxygen H + O₂ + M → HO₂ + M

Gas Phase Reaction Kinetics

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Steady-state intermediate concentrations and rate constants. HO2 results

Cited by 62 publications

References 2 publications

The rate constant of the reaction HO2 + COCO2 + OH

The rate constant of the reaction HO2 + COCO2 + OH

A flash photolysis‐resonance fluorescence study of the reaction of atomic hydrogen with molecular oxygen H + O2 + M → HO2 + M

Gas Phase Reaction Kinetics

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Product

Resources

About

The rate constant of the reaction HO₂ + COCO₂ + OH

The rate constant of the reaction HO₂ + COCO₂ + OH

A flash photolysis‐resonance fluorescence study of the reaction of atomic hydrogen with molecular oxygen H + O₂ + M → HO₂ + M