Reactions with Elements and Compounds

In a simulation of atmospheric-pressure ammonia flames, the Arrhenius expression k= 1 X io T° exp(-8.4 kJ mor VRT) cm mor s was used for reaction (2) N2H3 H - N2H2 H2 [7]. Reaction (2) was mentioned as one step in the photolytic decomposition of hydrazine [8]. 

A pKg value of 7.1 0.1 was derived for the acid-base equilibrium N2H4 N2H3 H by monitoring radiolyzed aqueous hydrazine solutions with an UV absorption spectrometer [13]. 

Oxygen. A lower limit for the rate constant, k 3xio L mor s was derived for the reaction N2H3 + 02 + 0H - OJ+ N2H2 + H2O in radiolyzed aqueous alkaline solutions of hydrazine containing oxygen [14]. 

In a simulation of atmospheric-pressure ammonia flames, the Arrhenius equation k3 = 2xio exp( —4.2 kJ mol VRT) was used for the reaction (3) N2H3 + 0- N2H2 + OH [7]. An upper limit of k3 5 x 10 cm mol s was determined in an investigation of the gas-phase reaction system N2H4 + O at room temperature. For the reaction path (4) N2H3 + 0- NH2 + HN0, a rate constant of k4 = 4xl0 cm -mol s was derived [2]. A theoretical study of the kinetics of NH3-O2 flames yielded the rate constant k4 = 10 cm -mol s which was used in a simulation of the reaction mechanism [17]. 

Miscellaneous. The oxidation of N2H3 by Fe and Cu in aqueous solutions gives N2H2 which in turn decomposes to give N2. The oxidation by Cu at pH 0.6 and 323 K is about 1200 times faster than the oxidation by Fe [18]. 

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