Reduction potential of the nitrate radical in aqueous solution

The pulse radiolysis of nitric acid solutions resulted in the conversion of the hydroxyl radical into the nitrate radical until equilibrium was established. Attainment of equilibrium was found to be more rapid for acid solutions with concentrations over 0.5 M. Formation of the nitrate radical proceeded via first-order kinetics for 0.5 to 1.5 M nitric acid solutions, while formation of the radical in 0.2 M and 0.3 M was inadequate due to the decay of the hydroxyl and nitrate radicals during the establishment of equilibrium.