Kinetics of Nitrogen Atom Recombination

Abstract

The rate of recombination of nitrogen atoms in the nitrogen afterglow has been measured in a flow system using NO as a titrant and determining the NO content continuously by mass spectrometer. Above about 3 mm of mercury the reaction is predominantly homogeneous and third order. The rate constant, 5.7×10¹⁵ cc² mole^—2 sec^—1, is independent of temperature in the interval studied (195–450°K). The rate is reduced by substituting helium or argon for N₂ as the third body, the ratios of the third‐order rate constants with these third bodies being about the same as those for recombination of iodine and bromine atoms. Below about 3 mm of mercury a pseudo‐first‐order wall recombination becomes important. The recombination coefficient was found to be 1.6×10^—5 on a glass wall that undoubtedly was partly poisoned by water.