Autoxidation of NO in aqueous solution

✍ Scribed by Hani H. Awad; David M. Stanbury

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 394 KB
• Volume: 25
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550250506

✦ Synopsis

Abstract

The reaction of NO with O~2~ has been investigated in aqueous solution. As demonstrated by ion chromatography, the sole product is NO~2~^−^. Kinetic studies of the reaction by stopped‐flow methods with absorbance and conductivity detection are in agreement that the rate law is ‐d[O~2~]/d__t__=k[NO]^2^[O~2~] with k = 2.1 × 10^6^ M^−2^ s^−1^ at 25°C. This rate law is unaffected by pH over the range from pH 1 to 13, and it holds with either NO or O~2~ in excess. By studying the reaction over the temperature range from 10 to 40°C, the following activation parameters were obtained: Δ__H__^≠^ = 4.6 ± 2.1 kJ mol^−1^ and Δ__S__^≠^=−96 plusmn; 4 J K^−1^ mol^−1^. © 1993 John Wiley & Sons, Inc.