Kinetic study of the reaction of hydrogen atoms with hydrogen chloride

Abstract

The reaction of hydrogen atoms with hydrogen chloride has been studied in a discharge-flow system using electron spin resonance detection of H-atoms and mass spectrometric analysis. The Arrhenius relation log(k₁/dm³ mol^–1 s^–1)=(9.67 ± 0.10)–[(13 300 ± 700)J mol^–1/2.303 RT] was obtained for the rate constant of the initial step H + HCl → H₂+ Cl (1), over the temperature range 298–521 K. This equation, together with literature values for the rate constant of the reverse reaction, gives satisfactory agreement between the rate constant ratio and the thermodynamic equlibrium constant, in contrast to earlier reports.