Oxygen and Nitrogen Isotope Effects in the Decomposition of Ammonium Nitrate

Abstract

The isotopic composition of the products of the controlled thermal decomposition of ammonium nitrate has been studied. It has been found that small amounts of water are necessary to initiate the decomposition of ammonium nitrate. N15H4NO3 has been found to yield exclusively the isomer N15N14O. Some inferences are drawn from this observation regarding the mechanism of the reaction. Oxygen and nitrogen isotope effects accompanying the decomposition have been studied with material of ``natural'' isotopic composition. Satisfactory agreement is found between the experimental results and theoretical calculations. A method for the isotopic analysis of nitrates for O18 is outlined.