A SHOCK-TUBE STUDY OF THE REACTIONS OF H-ATOMS WITH COS, CS2, AND H2S

Reactions of H atoms with COS, CS2, and H2S were studied behind reflec ted shock waves at temperatures between 1170 K and 1830 K and pressure s around 1.0 bar by applying atomic resonance absorption spectroscopy (ARAS) for time-resolved measurements of H atoms at L(alpha). The ther mal decomposition of a few ppm ethyl iodide (C2H5I) was used as a H-at om source. In the presence of a large excess of the molecular reactant COS, CS2, or H2S, a consumption of H was observed which follows a pse udo first-order rate law. Rate coefficients for the reactions: (R1) H + COS ((k1))--> CO + SH (R2) H + CS2 (k2)--> CS + SH (R3) H + H2S (k3) --> H-2 + SH were determined to be: k(1) = 2.4 x 10(14)exp(-3415 K/T) cm(3)mol(-1)s(-1) k(2) = 1.4 x 10(15)exp(-9250 K/T) cm(3)mol(-1)s(-1) k(3) = 2.5 x 10(14)exp(-2890 K/T) cm(3)mol(-1)s(-1).