1. There is some uncertainty in the heat of reaction of (37). However, it lies between 20 and 30 kcal/mole, so that this reaction is very fast at re-entry temperatures and is the primary fate of HCO. The energy for reaction (38) is about 46 kcal/mole,74and the rate constant is about 1010exp(-46,000/RT7) //mole sec which corresponds to a lifetime for the H02radical of about 106collisions at 2000°K. Other radical decomposition reactions are important also and will be discussed subsequently.
2. THE CHEMICAL KINETICS OF SODIUM IN RE-ENTRY