Chemical reaction rates shock-tube method

Recent advances in the measurement of high-temperature reaction rate constants are discussed. The studies carried out by shock tube methods are particularly considered because these results are important not only in theoretical chemical kinetics but also in practical applications. The work on five chemical reactions are reviewed in detail. These are D +... 

The importance of developing an appropriate theory became increasingly evident. Although theory only provides relatively inaccurate rate constants, it nevertheless predicts the range of the rate constant variation and/or its temperature dependence. This is often very helpful in the elucidation of the reaction mechanism. Equally important was the development of experimental methods of creating highly non-equilibrium conditions such as the shock tube technique, flash photolysis and various kinds of chemical activation. 

Single-pulse shock tube studies of the thermal dehydrochlorination reactions of chlorocyclopentane and chlorocyclohexane at temperatures of 843-1021 K and pressures of 1.4-2.4 bar have been carried out using the comparative rate technique. Absolute rate constants provided a self-consistent temperature scale of use in comparison with chemical systems studied with different temperature standards. Quantum chemical methods have been used to compute the structure and energies of reactants, products, and transition states. The computations were used, in conjunction with experimentally determined rate constants, to develop Rice-Ramsperger-Kassel-Marcus (RRKM)/ Master Equation models and thereby allow extrapolation of the experimental data over an extended range of temperatures. 

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