THE DISSOCIATION RATE OF HYDROGEN FLUORIDE BEHIND INCIDENT SHOCK WAVES

The rate of dissociation of hydrogen fluoride behind incident shock waves has been studied in the temperature range of 3700 to 6100K. Gaseous mixtures containing 0 to 4 hydrogen fluoride, 0 to 6 molecular fluorine, and 0 to 0.5 molecular hydrogen in an argon carrier were used in this study. The course of the dissociation was followed by monitoring the emission intensity of the 1-0 band of hydrogen fluoride at 2.5 microns. Resort was made to a determination of initial reaction rates to obtain values for the rate constant of the reaction HF M H F M. The effect of excess fluorine upon the initial reaction rate demonstrated that the reaction F HF F2 H is inconsequential 9 to the present study. Similarly, it was found that atomic fluorine has roughly the same third-body efficiency as argon for the recombination of H and F. Computer calculations based upon the whole reaction profile and including all the data were used to obtain a value for the rate of the hydrogen exchange reaction HF H H2 F. The data were too scattered to allow an accurate determination of the temperature dependencies of the pre-exponential factors.