SELENIUM ISOTOPE EFFECTS IN THE REDUCTION OF SODIUM SELENITE AND OF SODIUM SELENATE

Abstract

Selenium isotope effects in the reduction of sodium selenite and of sodium selenate have been studied. Rate constant ratios for the 76Se and 82Se species have been determined for the reactions Seiv → Se0 (1.017), Sevi → Seiv (1.018), and Se0 → Seiv (1.010) at room temperature. Theoretical predictions of the first two ratios, from the use of models in which the rate-controlling steps are assumed to be Se—O bond cleavages in SeO32− and SeO42−, respectively, lead to predictions in good agreement with experiment.