ESR Measurement of the Reaction between H Atoms and N2H4

An ESR atom detection method has been used to measure the rate of the reaction of H atoms with hydrazine, over the temperature interval 300–540°K. From the Arrhenius plot the specific rate constant for the reaction H+N₂H₄=N₂H₃+H₂ was found to be ${\text{(1.5\hspace{0.17em}±\hspace{0.17em}0.3)\hspace{0.17em}×\hspace{0.17em}10}}^{12}\exp \text{[(−\hspace{0.17em}1300\hspace{0.17em}±\hspace{0.17em}200)\hspace{0.17em}/\hspace{0.17em}RT]}$ in units of cubic centimeters mole⁻¹·second⁻¹. Although the stoichiometry of the reaction was not determined a possible reaction sequence is deduced from a mass spectrometric analysis of the products. The value of this rate constant is in good agreement with the rate constant of 1.7 × 10¹¹cm³ mole⁻¹·sec⁻¹ measured by Gehring et al. over the temperature interval 251–315°K and the activation energy of 1300 ± 200 cal agrees fairly closely with the 2000 cal measured by Schiavello and Volpi.