The iron(II)–chromium(VI) reaction: an additional pathway first order in iron(II)
Abstract
The iron(II)–chromium(VI) reaction has been studied by platinum-electrode polarography at low (micromolar) iron(II) concentrations. Here an additional term first order in iron(II) appears in the rate equation, which is found to be –d[FeII]/dt=k1H[H+][HCrO4–][FeII]+k2H[HCrO4–][FeII]2/[Fe3+], with k1H= 234 l2 mol–4 s–1 and 10–8k2H= 6·92 l4 mol–4 s–1 at 20 °C and ionic strength 1·00 mol l–1 in sodium perchlorate medium with 0·025–0·065M perchloric acid.