Reaction of carbon atoms, C (2p2, 3P) with C3H4(allene and methylacetylene), C3H6(propylene) and C4H8(trans-butene): Overall rate constants and atomic hydrogen branching ratios.

2004 ◽  
Vol 6 (23) ◽  
pp. 5396 ◽  
Author(s):  
Jean-Christophe Loison ◽  
Astrid Bergeat
Keyword(s):  
Rate Constants ◽  
Atomic Hydrogen ◽  
Branching Ratios ◽  
Trans Butene

Untersuchung konkurrierender Reaktionen in strömenden Kohlenwasserstoff-Gemischen / Investigation of Competing Reactions in Flowing Mixtures of Hydrocarbons

1974 ◽  
Vol 29 (4) ◽  
pp. 642-649 ◽  
Author(s):  
R. Laupert ◽  
G. von Bünau
Keyword(s):  
Rate Constants ◽  
Atomic Hydrogen ◽  
Relative Rate ◽  
Experimental Conditions ◽  
Kinetic Evaluation ◽  
Alkyl Radicals ◽  
Relative Rate Constants ◽  
Flow Apparatus ◽  
Competing Reactions

The reactions of atomic hydrogen with propene, butene-2, and trimethylethylene, and with mixtures of these olefins with ethylene have been studied using flow apparatus. It was found that under the experimental conditions intermediate alkyl radicals reacted practically only with atomic hydrogen. This made possible a kinetic evaluation of the results yielding numerical values of several relative rate constants of competing intermediate reactions.

Shock-wave observations of rate constants for atomic hydrogen recombination from 2500 to 7000 °K: collisional stabilization by exchange of hydrogen atoms

1969 ◽  
Vol 310 (1501) ◽  
pp. 253-276 ◽  
Keyword(s):  
Shock Waves ◽  
Rate Constant ◽  
Rate Constants ◽  
Atomic Hydrogen ◽  
Functional Form ◽  
Kcal Mole ◽  
Hydrogen Atoms ◽  
Hydrogen Molecules ◽  
Hydrogen Recombination ◽  
Equilibrium Dissociation

Rate constants for the recombination of atomic hydrogen with hydrogen molecules, hydrogen atoms, and argon atoms as the third bodies are presented in functional form for the range of temperatures from about 2500 to 7000 °K and are critically compared with the results of other workers. The rate constants are evaluated from detailed analyses of spectrum-line reversal measurements of the fall in temperature accompanying dissociation behind shock waves in gas mixtures containing 20, 40, 50 and 60% of hydrogen in argon. The rate constants for recombination with hydrogen molecules ( k -1 ) and argon atoms ( k -3 ) fit the equations log 10 k -1 = 15.243 - 1.95 x 10 -4 T cm 6 mole -2 s -1 , log 10 k -3 = 15.787 - 2.75 x 10 -4 T cm 6 mole -2 s -1 , with a standard deviation of 0.193 in log 10 k -1 . The rate constant for recombination with hydrogen atoms is about ten times larger than these at 3000 °K and shows a steep inverse dependence on temperature ( ~ T -6 ) above 4000 °K. Below this temperature the power of this dependence decreases rapidly and there is strong evidence that the value of this rate constant has a maximum around 3000 °K. This behaviour is interpreted on the basis of a process of collisional stabilization by atom exchange, requiring an activation energy around 8 kcal mole -1 and taking place under conditions of vibrational adiabaticity. The over-all results indicate that the assumption of equality between the equilibrium constant and the ratio of the rate constants for dissociation and recombination is valid throughout the region of non-equilibrium dissociation and at all temperatures in the shock waves examined.

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