Gaseous Reaction Rates at High Temperature. I. The Dissociation of Carbon Dioxide

Abstract

The rate of dissociation of carbon dioxide has been measured in the temperature range 3000°—5000°K. The amount of carbon dioxide was varied from 1% to 10% in a diluent of argon or nitrogen. The concentration of the mixture was varied from 0.11×10−5 to 0.49×10−5 mole/cc. It is shown that the decrease in temperature and increase in density caused by the endothermic dissociation must be considered in the analysis of the data. A computer program was employed to account for the effect of the changes in temperature and density on the observed rate of dissociation. The rate constants for the reaction CO2+M→CO+O+Mwere determined to be k1,Ar=7.11×1011T12exp(−84 500/RT) cc/mole·secwith argon as the diluent and k1,N2=5.33×1011T12exp(−79 600/RT) cc/mole·secwith nitrogen as the diluent. The probable dissociation mechanism also is discussed.