Reaction between sodium and ethyl chloride

To calculate the rate constant for the reaction between atomic sodium and ethyl chloride in the gas phase. 

In the diffusion flame method developed by von Hartel and Polanji (Z. physikal. Chem. B 1930,11, 97) sodium vapour is introduced throu a nozzle into an excess of organic halide and the extent of penetration before it is completely consumed by reaction is measured. In an experiment made by Cvetanovic and Le Roy (J. Chem. Phys. 1952, 20, 1016) at 532.7 K, a stream of sodium vapour at a partial pressure = 8.3 x 10 mm Hg in nitrogen carrier gas was passed through a nozzle of radius r = 0.125 cm into a stream of nitrogen and ethyl chloride vapour at a partial pressure p = 2.5 x 10 mm Hg. The radius R of the spherical zone of reaction made visible by illumination with sodium D-line resonance radiation was 1.55 cm. The partial pressure P of sodium at the visibility limit was estimated to be 7 X 10 mm Hg. The diffusion coef5cient D of sodium in the reaction mixture is 130 cm s.  

The observation of a spherical zone of reaction shows that the transport of sodium through the reaction zone is effectively due solely to diffusion. Application of stationary-state conditions to the flame zone gives for the bimolecular rate constant of the reaction 

There is an interesting review of the results obtained by this technique by Warhurst (Quart. Rev. Chem. Soc. 1951,5,44). An ingenious development of the method whereby the steady-state temperature pattern through the reaction zone is measured has enabled Garvin and Kistiakowsky (J. Chem. Phys. 1952, 20,105) to study the kinetics of the combination of boron trifluoride with amines. 

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