REACTIONS OF H2O3 IN PULSE-IRRADIATED FE(II)-O2 SYSTEM

G[Fe(III)] is measured in pulse-irradiated O2-saturated solutions of 20 to 160 μMFe(II), at the pH's 0.46, 1.51, and 2.74 H 2SO4 and HClO4 and with dose rates between 1 and 8 krad/1 Msec pulse. Based on homogeneous kinetics, the results are interpreted by a system of 18 reactions. The formation of the hydrogen sesquioxide H2O3 as an intermediate in the reaction OH+HO2 → H2O3→ H2O+O 2 is confirmed. In the absence of Fe(II), G(H2O 3) varies from 2.04 at pR 0.46 to 1.57 at H 2.74. The rate constant [H2O3+ Fe(Ii)] = 6.07times;m-Lsec-1 At The Ph's Studied. The Direct Reaction, Oh+ho2=h2o+o2, Does Not Take Place. In Hiso4, At Ph 0.46, 151, And 2.74 And In Hclo 4 At Ph 0.46 And 1.51, The Complexes Of Fe(Iii) Produced By The Radiation Reach Equilibrium Before They React With Ho2.However, Equilibrium Is Not Reached In Hclo4At Ph 2.74,Where The Effective Rate Constant K (Ho2+fe (Iii) ] Is 6.2 Times Its Value When Fe (Iii) Is In Its Equilibrium Form. This Ratio Is Constant Over The Dose Rate Range Studied. With Dose Rates Up To 64 Krad/1.4 Jusec Pulse Grjfe(Iii)] And G(H2) Were Measured In The Air Saturated 1-Mm Feso4 Dosimeter And G[fe(Iii)] In The O 2 Saturated 10-Ram Fes04 Dosimeter, Each In 0.4kh2so4. G[fe(Iii)] Decreases In Both Dosimeters Less Rapidly With Increasing Dose Rate Than Was Found By Earlier Workers. The Principal Reason For The Decrease Is The Failure Of O2 To Scavenge The H Atoms At High Dose Rates. Excellent Agreement Is Obtained Between Experiment And Theory Except At High Dose Rates, Where The Calculated G[fe(Iii)]'s Are Slightly Too High In Both Dosimeters.