Dissociation of FeO2 in shock waves: Analysis of the forward and backward reactions

The rate constant for the dissociation of FeO2 molecules behind reflected s hock waves is measured in the temperature range of 1930-2225 K at a concent ration of the gas of (6.0-8.0) x 10(-6) mol/cm(3). A model of the dissociat ion-recombination reaction FeO2 + M = Fe + O-2 + M that accounts for the el ectronically excited states of FeO2 satisfactorily describes the entire set of data for the forward and backward processes. The rate constants in the low- and high-pressure limits are described by the following expressions: d issociation at T = 1000-2300 K (the activation energy, in kJ/mol), k(0,dis) (T) = 3.3 x 10(18)(T/1000)(-1.8)exp(-357.7/RT), cm(3) mol(-1) s(-1); k(infi nity), (dis)(T) = 4.8 x 10(14)(T/1000)-(0.913)exp(-357.7/RT) s(-1); recombi nation at T = 300-2300 K, k(0,rec)(T) = 1.1 x 10(18)(T/1000)(-0.88)exp(-18. 8/RT), cm(6) mol(-2) s(-1), k(infinity), (rec)(T) = 1.56 x 10(14)exp(-18.8/ RT) cm(3) mol(-1) s(-1). The experimentally measured dissociation rate cons tant for FeO2 is in good agreement with the available thermochemical data f or this molecule.