Dissociation Energy and Rate of Decomposition of C2N2

Abstract

The decomposition of cyanogen has been studied using shock wave heating. Kinetic and equilibrium concentrations of CN were obtained spectrophotometrically on 1, 5, and 10% solutions in Ar, in the incident and reflected shock regions. These data give C2N2=2 CN, ΔH0∘=125±8 kcal.The dissociation reaction proceeds via a second-order process with a rate constant fitted by kdiss=[(3.3×1012)/5.5!]T12(E/RT)5.5e−E/RT, cm3 mole−1 sec−1.The three-body recombination-rate constant is given by krec=2.3×1012(E/RT)3, cm6 mole−2 sec−1; E=125 000.Previous data on this reaction have been summarized and critically analyzed.