Kinetic Study for Aquation of $cis-[Co(en)_2(NH_3)Cl]^{2+}$ in $Hg^{2+}$ Aqueous Solution

A kinetic study was made to determine the mechanism of the aquation of aqueous solution. The progress of reaction was followed UV/vis-spectrophotometrically by a measurement of the absorbance at a specific wave length (530nm) of as a function of time. The experimental results have shown that the reaction rate is dependent upon the concentration of 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 . Activation parameters, , 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.