The kinetics of the reaction of chromium(II) with hydrazine, hydroxylamine and hydrazoic acid in perchlorate media: the formation of halogeno- and sulphato-complexes of chromium(II)

Abstract

The kinetics of the reduction of hydrazine, hydroxylamine, hydrazoic acid, and the azide ion by chromium(II) have been investigated in perchlorate media. In all cases the reaction is first order in [Cr^II] and first order in [substrate]. The rates are increased by the addition of halide and sulphate ions, and this is due to the competition of 1 : 1 chromium(II) complexes with Cr_aq²⁺ for the substrate. Formation constants are determined for these complexes, and their heats and entropies of formation are compared with the analogous iron(II) complexes.