View More View Less
  • 1 Institute of Isotopic and Molecular Technology P.O. Box 700 3400 Cluj-Napoca Romania
Restricted access


The rate of nitrogen isotope exchange between NO and HNO3 has been measured as a function of nitric oxide pressure 0.1–0.4 MPa for 1 and 2 M·1–1 HNO3. It is concluded that15N/14N exchange rate in NO–HNO3 system has a linear dependence of NO pressure as indicated by rate measurements at different NO partial pressure and constant overall pressure, by adding helium in reactor. Using the rate law:R=k[HNO3]2[N2O3] the15N/14N exchange rates for nitric acid concentrations 1.5–10 M·1–1 were calculated.