Kinetics and mechanism of oxidations by peroxodiphosphate ions. Part I. Oxidation of arsenic(III) in aqueous perchloric acid
作者:Surinder Kapoor、Yugul K. Gupta
DOI:10.1039/dt9760000473
日期:——
Peroxodiphosphate, [P2O8]4–, oxidises arsenious acid in perchloric acid medium according to equation (i). H4P2O8+ H3AsO3+ H2O → 2H3PO4+ H3AsO4(i) The mechanism essentially involves hydrolysis of the species [H2P2O8]2–, [H3P2O8]–, and H4P2O8, and the rate of the redox reaction is independent of the arsenic (III) concentration. The rate law when 2.5 > [HClO4] > 0.1 mol dm–3 is as in (ii), and the values of
过氧合二磷酸盐[P 2 O 8 ] 4–根据等式(i)氧化高氯酸介质中的砷酸。H 4 P 2 O 8 + H 3 AsO 3 + H 2 O → 2H 3 PO 4 + H 3 AsO 4(i)该机理实质上涉及[H 2 P 2 O 8 ] 2–,[H 3 P 2 O 8 ] –和H 4 P2 O 8,并且氧化还原反应的速率与砷( III)浓度无关。2.5> [HClO 4 ]> 0.1 mol dm –3时的速率定律与(ii)相同, k 2和k 3的值分别为(2.7±0.2)×10 –4和(8.65±0.3)×10在45°C时分别为–3 s –1。–d [P 2 O 8 ] / d t = k 2 [H 3 P 2 O 8 – ] + k 3 [H 4 P 2O 8 ](ii)反应速率与离子强度无关。丙烯酰胺,F - ,铜2+,锰2+,铁2+和磷酸盐对反应没有影响,但银+催化反应。