Kinetics of Silver (I)-Catalysed Oxidation of Indigo Carmine by Potassium Peroxydisulphate-Catalytic Kinetic Determination of Micro Amounts of Silver

Department of Chemistry, Andhra University, Waltair-530 003

Manuscript received 5 November 1977, revised 29 July 1978, accepted 3 October 1978

The kinetics of oxidation of indigo carmine by peroxydisulphate catalysed by silver (I) was investigated. The reaction is of first order with respect to peroxydisulphate and silver (I) and zero order in indigo carmine. Increase of ionic strength decreases the rate. The reaction mixture initiates vinyl polymerization. Activation parameters were calculated. The catalysed reaction was utilized for developing kinetic method for the determination of Ag (I) in micro gram concentrations (in the range 0.3-4.0 pg/ml) with an average error of 2%. The standard deviation, coefficient of variation and percentage error were also calculated.