DISTRIBUTION OF CE(IV) SPECIES IN HNO3-HCLO4 MEDIA AND DETERMINATION OF STABILITY-CONSTANTS OF THE NITRATE COMPLEXES

In this paper, the distribution of cerium (IV) species depending on th e charges of nitric acid-perchloric acid concentration at constant ion ic strength (I=1.0) was investigated. Cerium (IV), being a strong oxid ant, was utilized for investigating the oxidation kinetics of some ami no acids. Knowing the distribution of cerium (IV) species is beneficia l for better understanding this type of kinetics. Distribution of ceri um (IV) species in aqueous media was studied by measuring the total op tical absorbance of cerium (IV) species in different nitric acid-perch loric acid mixture solutions. The stability constants (K-1 and K-2) of the nitrate cerium complexes were determined spectrophotometrically f rom equilibrium data and from kinetic data concerning the eerie oxidat ion of amino acids. The magnitudes of the constants computed by these two separate methods were in accordance with each other.