The oxidation of iodide ion by chlorine dioxide has been studied by stopped-flow techniques at I = 1.0 M (NaClO4). The following two-term rate law was confirmed for the reaction: -d[ClO2]/dt = kI[ClO2][I-] + kII[ClO2][I-]2. The rate constants at 298 K and the activation parameters are kI = (1.87 ± 0.02) × 103 M-1 s-1, ΔHI‡ = 35.4 ± 0.7 kJ/mol, ΔSI‡ = -63.5 ± 2.3 J/(mol K), kII = (1.25 ± 0.04) × 104 M-2 s-1, ΔHII‡ = 36.7 ± 1.3 kJ/mol, ΔSII‡ = -43.2 ± 4.6 J/(mol K). Both the second- and third-order paths are interpreted in terms of an outersphere electron-transfer mechanism. The calculations based on the Marcus theory yield kI = 1358 M-1 s-1 for the second-order path.
|Number of pages||4|
|Publication status||Published - dec. 1 1997|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry