Temperature dependence of the rate constant and product channels for the bromine oxide + chlorine oxide reaction

1988 ◽  
Vol 92 (7) ◽  
pp. 1853-1858 ◽  
Author(s):  
Alan J. Hills ◽  
Ralph J. Cicerone ◽  
Jack G. Calvert ◽  
John W. Birks
Keyword(s):  
Temperature Dependence ◽  
Rate Constant ◽  
Bromine Oxide ◽  
Chlorine Oxide

Radiolysis studies on the corrosion inhibitors 1 -hexyn-3-ol, cinnamonitrile, and 1,3-diethyl-2-thiourea

1995 ◽  
Vol 73 (12) ◽  
pp. 2137-2142 ◽  
Author(s):  
A.J. Elliot ◽  
M.P. Chenier ◽  
D.C. Ouellette
Keyword(s):  
Hydrogen Atom ◽  
Hydroxyl Radical ◽  
Temperature Dependence ◽  
Rate Constant ◽  
Rate Constants ◽  
Corrosion Inhibitors ◽  
Hydrated Electron

In this publication we report: (i) the rate constants for reaction of the hydrated electron with 1-hexyn-3-ol ((8.6 ± 0.3) × 108 dm3 mol−1 s−1 at 18 °C), cinnamonitrile ((2.3 ± 0.2) × 1010 dm3 mol−1 s−1 at 20 °C), and 1,3-diethyl-2-thiourea ((3.5 ± 0.3) × 108 dm3 mol−1 s−1 at 22 °C). For cinnamonitrile and diethylthiourea, the temperature dependence up to 200 °C and 150 °C, respectively, is also reported; (ii) the rate constants for the reaction of the hydroxyl radical with 1-hexyn-3-ol ((5.5 ± 0.5) × 109 dm3 mol−1 s−1 at 20 °C), cinnamonitrile ((9.2 ± 0.3) × 109 dm3 mol−1 s−1 at 21 °C), and diethylthiourea ((8.0 ± 0.8) × 108 dm3 mol−1 s−1 at 22 °C). For cinnamonitrile, the temperature dependence up to 200 °C is also reported; (iii) the rate constant for the hydrogen atom reacting with 1-hexyn-3-ol ((4.3 ± 0.4) × 109 dm3 mol−1 s−1 at 20 °C). Keywords: radiolysis, corrosion inhibitors, rate constants.

Temperature dependence of the O+I(P21/2)→O+I(P23/2) quenching rate constant

2009 ◽  
Vol 105 (9) ◽  
pp. 094911 ◽  
Author(s):  
Pavel A. Mikheyev ◽  
David J. Postell ◽  
Michael C. Heaven
Keyword(s):  
Temperature Dependence ◽  
Rate Constant ◽  
Quenching Rate ◽  
Quenching Rate Constant

Kinetic studies of oxy-halogen radical systems

1968 ◽  
Vol 303 (1473) ◽  
pp. 207-231 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Chlorine Dioxide ◽  
Peroxy Radical ◽  
Kinetic Studies ◽  
Bromine Oxide ◽  
Chlorine Oxide ◽  
Direct Reactions ◽  
Rapid Reaction ◽  
Atomic Chlorine ◽  
Halogen Radical

Chlorine oxide radicals, ClO( 2 II , v " = 0) were obtained as a product of (a) the rapid reaction of Cl with chlorine dioxide at 300°K, Cl + OClO → ClO + ClO, (1) (b) the initiated thermal decomposition of OClO above 320°K, (c) the rapid reaction of Cl with ozone at 300°K, Cl + O 3 → ClO + O 2 . Bromine oxide radicals, BrO ( 2 II , v " = 0), have also been detected in the reaction of bromine atoms with ozone. The decay reaction of ClO radicals was second order in [ClO] at all temperatures studied (294 to 495°K). The decay of [ClO] in the presence of chlorine atom scavengers (H 2 , Br 2 , OClO) has also been studied. The direct reactions of ClO with H 2 (7), and with O 3 (9), were undetectably slow, with k 7 < 10 8.5 and k 9 < 10 9.5 cm 3 mole -1 s -1 at 294°K. The recombination of two ClO radicals probably takes place through a mechanism involving small concentrations of atomic chlorine and the short-lived, ClOO peroxy radical, ClO + ClO → k 2 C1 + ClOO, (2) ClOO + Cl → Cl 2 ( 1 ∑ + g , 3 II Ou+ + O 2 , (3) ClOO + M → Cl + O 2 + M . (4) Rate measurements gave k 2 = (7 ± 2) x 10 11 exp [(— 2500 ± 300)/ RT ] cm 3 mole -1 s -1 from 294 to 495°K. The present values for k 2 are compared with those found previously.

Radiolysis of Supercritical Water at 400°C: A Sensitivity Study of the Density Dependence of the Yield of Hydrated Electrons on the (eaq−+eaq−) Reaction Rate Constant

2016 ◽  
Vol 2 (2) ◽  
Author(s):  
Sunuchakan Sanguanmith ◽  
Jintana Meesungnoen ◽  
David A. Guzonas ◽  
Craig R. Stuart ◽  
Jean-Paul Jay-Gerin
Keyword(s):  
Temperature Dependence ◽  
Density Dependence ◽  
Rate Constant ◽  
Supercritical Water ◽  
Reaction Rate ◽  
Reaction Rate Constant ◽  
Sudden Drop ◽  
Alkaline Water ◽  
Hydrated Electrons ◽  
Neutral Water

The temperature dependence of the rate constant (k) of the bimolecular reaction of two hydrated electrons (eaq−) measured in alkaline water exhibits an abrupt drop between 150°C and 200°C; above 250°C, it is too small to be measured reliably. Although this result is well established, the applicability of this sudden drop in k(eaq−+eaq−)) above ∼150°C to neutral or slightly acidic solution, as recommended by some authors, still remains uncertain. In fact, the recent work suggested that in near-neutral water the abrupt change in k above ∼150°C does not occur and that k should increase, rather than decrease, at temperatures greater than 150°C with roughly the same Arrhenius dependence of the data below 150°C. In view of this uncertainty of k, Monte Carlo simulations were used in this study to examine the sensitivity of the density dependence of the yield of eaq− in the low–linear energy transfer (LET) radiolysis of supercritical water (H2O) at 400°C on variations in the temperature dependence of k. Two different values of the eaq− self-reaction rate constant at 400°C were used: one was based on the temperature dependence of k above 150°C as measured in alkaline water (4.2×108  M−1 s−1), and the other was based on an Arrhenius extrapolation of the values below 150°C (2.5×1011  M−1 s−1). In both cases, the density dependences of our calculated eaq− yields at ∼60  ps and 1 ns were found to compare fairly well with the available picosecond pulse radiolysis experimental data (for D2O) for the entire water density range studied (∼0.15–0.6  g/cm3). Only a small effect of k on the variation of G(eaq−)) as a function of density at 60 ps and 1 ns could be observed. In conclusion, our present calculations did not allow us to unambiguously confirm (or deny) the applicability of the predicted sudden drop of k(eaq−+eaq−) at ∼150°C in near-neutral water.

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