The kinetics and mechanism of oxidative decolorisation of Indigo carmine with 1-CBT in alkaline buffer medium have been spectrophotometrically investigated at ƛmax 610 nm and at the temperature of 301 K. The reaction exhibited a first order dependence of the rate on [IC] and [CBT] and fractional order dependence on [OH- ]. Inverse fractional order dependence on [BTA]. The variation of ionic strength of the medium did not affect the rate indicating that non ionic species involved in the rate determining step. The dielectric effect is negative. The reaction was studied at deferent temperatures and the activation parameters were deduced. Oxidation products were characterized. Test for free radicals was found to be negative. The derived rate law based on the proposed mechanism is in complete agreement with the observed kinetic data.
