The Formation of CrO2+2 in the Reaction of Cr2+ + O2 in Aqueous Acid Solutions

Abstract
The reduction rate of Cr3+ by eaq was determined, k8 = 1.7 × 1010 M−1 s−1. The reaction of Cr2+ with O2 was studied, k2 = 1.6 × 108 M−1 s−1. The spectrum of CrO2+2 was obtained both with the pulse radiolysis method and by mixing Cr2+ with excess of O2. It was shown that CrO2+2 decays slowly to yield HCrO4. The results suggest that the reaction of Cr2+ with O2 is a two electron transfer process.