Kinetics of Hydrogen Halides in Shock Waves. II. A New Measurement of the Hydrogen Dissociation Rate

Decomposition rates for H2, diluted in Ar, were studied behind incident shock waves over the temperature range 2900° to 4700°K. HCl and the infrared emission from this molecule were used in a manner to trace the course of decomposition of the H2. In terms of recombination rate constants, we found (cc, moles, sec units) k−3=1018T−1, k−4=2.5k−3, and k−5=20k−3, where the subscripts 3, 4, and 5 refer respectively to Ar, H2, and H as third bodies.