REDUCTION OF DODECATUNGSTOCOBALTATE(III) BY AQUEOUS-SOLUTIONS OF HYDRAZINIUM ION

The kinetics of the reduction of dodecatungstocobaltate (III) anion by hydrazinium ion has been studied in aqueous hydrochloric acid. The data are consistent with the rate law {A figure is presented} with k2 = (1.80 ± 0.05) X 10-2 mol-1 dm3 S-1, ΔH ‡ = 46.7 ± 0.8 kJ molp-1, and ΔS ‡ = -121 ±5 J K-1 mol-1 at I = 2.0 mol dm-3 (NaCl), [H+] = 0.1- 1.5 mol dm-3 and T = 24.5 °C. Added copper(II) ions catalysed the rate and the reduction is interpreted in terms of the outer-sphere mechanism. © 1990.