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  • 1 Pakistan Institute of Nuclear Science and Technology Chemistry Division P.O. Nilore Islamabad Pakistan
  • 2 The Islamia University of Bahawalpur Department of Chemistry Bahawalpur Pakistan
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Abstract  

The complexation of uranyl ion with acetate ions was investigated in 20% ethanolic solution by using cyclic voltammetry. The uranium formed 1:1 and 1:2 complexes with acetate ions. The values of log β1 and log β2 for uranyl acetate complexes were 2.05 ± 0.08 and 5.25 ± 0.06 respectively. The diffusion coefficient and heterogeneous rate constants for the reduction of uranyl ion at hanging mercury drop electrode in 20% ethanolic solution of acetate ions were 0.43 × 10−5 cm2 s−1 and 2.26 × 10−3 cm s−1, respectively. Thermodynamic parameters were also evaluated by finding the effect of temperature on the heterogeneous rate constants. The values of ΔH*, ΔS* and

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were 2.52 kJ mol−1, −43.8 J mol−1 K−1 and 15.57 kJ mol−1. The positive values of ΔH* and
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indicated that electrochemical reduction of uranyl ions in ethanolic solution of acetate ions is an endothermic and non-spontaneous process.