物理化学学报2007，Vol.23Issue(7)：1013-1017,5.
Mn(Ⅱ)和Ce(Ⅳ)离子对铬酸氧化乳酸的影响
Effect of Mn(Ⅱ) and Ce(Ⅳ) Ions on the Oxidation of Lactic Acid by Chromic Acid
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作者信息
- 1. Department of Chemistry, Jamia Millia Islamia (Central University),New Delhi-110025,India;Department of Chemistry, Jamia Millia Islamia (Central University),New Delhi-110025,India
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摘要
Abstract
The kinetics and mechanism of lactic acid oxidation in the presence of Mn(Ⅱ) and Ce(Ⅳ) ions by chromic acid were studied spectrophotometrically. The oxidation of lactic acid by Cr(Ⅵ) was found to proceed in two measurable steps, both of which gave pyruvic acid as the primary product in the absence of Mn(Ⅱ).2Cr(Ⅵ)+2CH3CHOHCOOH→ 2CH3COCOOH+Cr(Ⅴ)+Cr(Ⅲ)Cr(Ⅴ)+CH3CHOHCOOH→Cr(Ⅲ)+CH3COCOOHThe observed kinetics was explained due to the catalytic and inhibitory effects of Mn(Ⅱ) and Ce(Ⅳ) on the lactic acid oxidation by Cr(Ⅵ). The reactivity of lactic acid depends upon the experimental conditions. It acts as a two- or threeequivalent reducing agent in the absence or presence of Mn(Ⅱ). It was examined that Cr(Ⅲ) products resulting from the direct reduction of Cr(Ⅵ) by three-equivalent reducing agents. The oxidation of lactic acid follows the complex order kinetics with respect to [lactic acid]. The activation parameters Ea, △H#, and △S# were calculated and discussed.关键词
Kinetics/Lactic acid/Cr(Ⅵ)/Ce(Ⅳ)/Mn(Ⅱ)/OxidationKey words
Kinetics/Lactic acid/Cr(Ⅵ)/Ce(Ⅳ)/Mn(Ⅱ)/Oxidation分类
化学化工引用本文复制引用
..Mn(Ⅱ)和Ce(Ⅳ)离子对铬酸氧化乳酸的影响[J].物理化学学报,2007,23(7):1013-1017,5.
