Kinetics and mechanism of Ag (I) catalysis in peroxodisulphate oxidation of tris(2,2'-bipoyridine)fe(II) in aqueous acid media

The kinetics of Ag+ catalysed oxidation of tris(2,2'-bipyridine)iron(II) complex by the peroxodisulphate ion (S/sub 2/O/sub 8/) in aqueous acidic media have been investigated spectrophotometrically at lambda max 522 run, the wavelength of maximum absorption of complex ion. It was determined that the rate of oxidation of (Fe(2,2'-bipyridine)3P+ by S/sub 2/O/sub 8/ ion is independent of the concentration of (Fe(2,2'-bipyridine)3P+ and H+ (within pH range of 3.8-4.8), but first order dependent with respect to the concentrations of S/sub 2/O/sub 8/ and Ag+ in the 4.16x 10/sup -4/ -16.7x 10/sup -4/ mol/dm3 and 4.16x 10/sup -5/ - 16.7x 10/sup -5/ mol/dm/sup 3/ ranges, respectively. Experimental results confirm the validity of the suggested mechanism. (author)