The study deals with the kinetic spectrophotometric studies on the microgram determination of Ir(III), while it catalyzes the alanine and hexacyanoferrate(III) redox system in aqueous alkaline medium. The reaction was followed by noting the absorbance of the reaction mixture after 5,10,15,20 min from the start of the reaction. Linear calibration curves were obtained in terms of type ‘A’, type ‘B’, type ‘C’, type ‘D’, type ‘E’, type ‘F’ and type ‘G’, i.e. A5 or A10 or A15 or A20 or A25 or [dA/dt]i or k1 vs. [Ir(III)] plots respectively. (where A5, A10, A15, A20, A25 are the absorbance values after 5, 10, 15, 20, 25 min from the start of the reaction respectively. The stoichiometry of the reaction was studied by estimating the amount of hexacyanoferrate(II)ions produced after definite interval of time with standard solution of ceric(IV) sulphate using ferroin as redox indicator. The studies show that two moles of hexacyannoferrate(III) are used for the oxidation of one mole of alanine. Based on the experimental results, it can be proposed that reaction proceeds through complex formation between anion of alanine and Ir(III) which slowly disproportionate into Ir(I) and intermediate product. Ir(I) reoxidized by two moles of hexacyannoferrate(III) ions to Ir(III) through electron transfer mechanism & the intermediate product decomposes to final product.
Author(s) Details:
Shakunj Rajput,
Department of Chemistry, Government Degree College, Bhupatwala, Haridwar (U.K), India.
