STOICHIOMETRY, KINETICS AND MECHANISM OF THE SILVER(I) CATALYZED OXIDATION OF HYPONITROUS ACID WITH PEROXODISULFATE ION IN ACID PERCHLORATE SOLUTIONS

The title reaction provides the first indirect kinetic evidence for the well known assumed complex formation between S2O82- and Ag+. It is al so the first report of a reaction with comparable rates of oxidation of hyponitrous acid and water in the (S2O82 + Ag+) system. Hyponitrous acid is the first reported substrate which is not oxidised by SO4-. Peroxodisulphate ion and hyponitrous acid react in presence of silver(I) as in (i) 5S2O82- + 1.5H2N2O2 + 5H2O --> 10HSO4- + 3HNO2 + O2 ... (i) according to the rate law (ii), -d[S2O82-]/dt = (k0 + 3k1k3[H2N2O2] / k2+k3[H2N2O2])[S2O82-][Ag(I)] ... (ii) k0 and k1 were found to be (4.2 +/- 0.2) X 10(-3) and (5.0 +/- 0.2) X 10(-3) mol-1 dm3 s-1 at 25-degrees and I = 0.11 mol dm(-3).