Reactions in Highly-Rarefied and Diffusion Flames Reaction

1 Reactions in Highly-Rarefied and Diffusion Flames Reaction M + X 

The study of chemical reactions in highly-rarefied flames has proved to be of great value in the investigation of elementary reactions of free atoms and radicals. Highly-rarefied flames are specific in that they are sustained at very low 

Another feature of reactions M -j- Xg is that, as stated above, an admixture of hydrogen to a Na + Clg flame induces the generation of a considerable amount of HCl, besides NaCl. This indicates the presence of atomic chlorine in the Na + Clg flame which is in agreement with the reaction mechanism 

The energy liberated in process (I) is insufficient to excite an atom of sodium in the Na + Xg reaction. Thus, the source of the excitation energy of the sodium atom can be only process (II) which liberates an energy always higher than the excitation energy of the sodium atom (see [230] and [459]). 

Consider also the reactions of alkali metal atoms with hydrogen halides. Those of Na and K with HCl, HBr, and HI have been studied by M. Polanyi and coworkers. The reaction rates were found to be controlled by the magnitude and sign of the heat of reaction M + HX = MX + H, the activation energy of 

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