ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 32, Number 3
JKCSEZ 32(3)
June 20, 1988 

A kinetic study was made to determine the mechanism of the aquation of cis-[Co(en)2(NH3)Cl]2+ in Hg2+ aqueous solution. The progress of reaction was followed UV/vis-spectrophotometrically by a measurement of the absorbance at a specific wave length (530nm) of cis-[Co(en)2(NH3)Cl]2+ as a function of time. The experimental results have shown that the reaction rate is dependent upon the concentration of Hg2+ that act as a catalyst. And it was found that the overall reaction proceed with second order, first order with respect to Co(Ⅲ) complex and Hg2+. Activation parameters, ΔH≠and ΔS≠, were obtained as 12.9 kcal/mol and -19.3 e.u., respectively. We have proposed a plausible reaction mechanism which is consistent with the observed rate equation.