Absolute rate constant for the reaction OH+NH3→NH2+H2O

The kinetic behavior of OH radicals in the presence of a large excess of NH₃ has been studied by pulsed photolysis. The OH radicals were produced by vacuum‐uv photolysis of H₂O and were monitored by resonance fluorescence. The rate constant for the reaction of OH with NH₃ was determined to be ${\text{1.5(± 0.4)× 10}}^{\text{−13}}\hspace{0.17em}{\mathrm{cm}}^3\hspace{0.17em}{\mathrm{molecule}}^{\text{−1}}·{\sec }^{\text{−1}}$ at 298°K. The significance of this result is discussed with regard to atmospheric chemistry.