A High-Temperature Photochemistry Study of the H + HCl -> H2 + Cl Reaction from 298 to 1192 K

Article abstract of DOI:10.1021/j100109a026

Rate coefficients for the reaction between ground-state H atoms and HCl have been measured using the HTP (high-temperature photochemistry) technique.The hydrogen atoms were generated by flash photolysis of NH3, and the relative atom concentrations were monitored by time-resolved resonance fluorescence.The data in the 298-1192 K range are well fitted by the expression k₁(T) = 2.8x10^-11exp(-2082 K/T) cm³ molecule^-1 s^-1 with 2? precision limits of +/-6percent to +/-12percent, depending upon temperature, and corresponding 2? accuracy limits of about +/-23percent.A transition state theory calculation based on a semiempirical London-Eyring-Polanyi-Sato potential energy surface leads to excellent agreement with the experimental results.By combining the present best fit with current equilibrium data, we derive for the reverse reaction k_-1(T) = 4.9x10^-11exp(-2567 K/T) cm³ molecule^-1 s^-1.