Kinetics of the Homogeneous Exchange Reaction: NH3plus;D2rarr;NH2D plus;HD. Singlehyphen;Pulse Shockhyphen;Tube Studies

摘要

The homogeneous exchange reaction between ammonia and deuterium was studied in a singlehyphen;pulse shock tube over a wide range of compositions and initial pressures within the 1150ndash;1450deg;K temperature range. The rate of production of HD in the early stages of the reaction, in the composition range 0.67ndash;4percnt; NH3and 0.67ndash;4percnt; D2in argon is given bydlsqb;HDrsqb;sol;dtthinsp;equals;thinsp;kblsqb;Arrsqb;0.38lsqb;NH3rsqb;0.61lsqb;D2rsqb;1.01, wherekbthinsp;equals;thinsp;1013.0thinsp;plusmn;thinsp;0.3explsqb;minus;lpar;37.2thinsp;plusmn;thinsp;1.0rpar;thinsp;times;thinsp;103sol;RTrsqb;cc moleminus;1middot;secminus;1. The contribution of a chain mechanism to the exchange process was ruled out. A mechanism based on vibrational excitation of the deuterium molecule to a critical vibration level as a slow step prior to the atom switching step is proposed.