Pulse Radiolytic Studies of Aqueous Mn(ClO sub 4 ) sub 2Solutions. Progress Report,September 1, 1976--July 1, 1977.

摘要

Using Mn(ClO sub 4 ) sub 2 ,the reactions of Mn exp 2+with CO sub 2- , e exp - /sub aq/,OH,and O sub 2-were studied at pH 6.7. The following reaction rate constants were measured: k(Mn exp 2+ +CO sub 2- ) < 2 x 10exp 5 M exp -1sec exp -1 , k(Mn exp 2+ + e exp - /sub aq/ = (9 +- 2) x 10exp 6 M exp -1sec exp -1 (ionic strength 0.15to 0.5 M), k(Mn exp 2+ +OH) = (3.4 +- 0.8) x 10exp 7 M exp -1sec exp -1 ,and k(Mn exp 2 + O sub 2 -) = (1.1 +- 0.2) x 10exp 8 M exp -1sec exp -1 (0.01 M formate), O sub 2-radical ions react with Mn exp 2+and produce Mn exp 3+or MnO sub 2+ions. The reaction was found to be reversible,and an equilibrium constant K = (1.5 +exp - 0.6) x 10exp 4 M exp -1was measured at pH 6.7. Mn exp 2+ ,however,does not catalyze the dismutation of O sub 2- . The disporportionation of Mn(III) (as MnOH exp 2+ ) and the subsequent nucleation of the product MnO sub 2are reported. (ERA citation 02:060566)