Dissociation rate measurements in SO 2 + Ar mixtures behind incident shock waves

Abstract

Dissociation rates of SO 2 in SO 2 + Ar mixtures at 6%, 11%, 15% and 20% of SO 2 were measured behind incident shock waves over a temperature range 4000–6000 K at initial pressures 1.0 to 2.5 Torr. The recorded laser schlieren signals exhibited two exponentials, the faster one due to vibrational relaxation and the slower one due to dissociation. The initial dissociation rate was calculated from the value of the density gradient at the point of intersection of the two exponentials. A least-squares analysis of the experimental data yielded the following empirical relations: k SO 2Ar = 3.34 × 10 15 exp(−107.6 kcal mole −1/ RT) cm 3/mole s, k SO 2SO 2 = 5.02 × 10 14 exp(−66.6 kcal mole −1 kcal mole −1/ RT) cm 3/mole s.