HNO3介质中U(Ⅳ)还原Np(Ⅴ)的动力学
Kinetics of Reduction of Np(Ⅴ) by U(Ⅳ) Ions in Nitric Acid Media
-
摘要: 采用分光光度法研究了HNO3溶液中U(Ⅳ)还原Np(Ⅴ)的反应，获得了动力学方程-dc (Np(Ⅴ))/dt=kc(Np(Ⅴ))c0.7 (U(Ⅳ))c1.9 (H+)c (NO-3)，25℃时反应速率常数k=(6.37±0.49)×10-3 L3.6/(mol 3.6•min)，反应活化能Ea=60.13 kJ/mol。结果表明，浓度为0~4.2×10-2mol/L的U(Ⅵ) 对U(Ⅳ)还原Np(Ⅴ)的反应几乎没有影响，并探讨了可能的反应机理。Abstract: The reduction of NpO+2 to Np4+ by U(Ⅳ) in nitric acid solution has been studied by spectrophotometric method, and the rate equation is described by: -dc(Np(Ⅴ))/dt=kc(Np(Ⅴ))c0.7 (U(Ⅳ))c1.9 (H+)c(NO-3) where k =(6.37±0.49)×10-3 L3.6/(mol3.6•min) at 25℃. The activation energy is estimated to be 60.13 kJ/mol. U(Ⅵ) with the concentration of 0-4.2×10-2 mol/L has little effect on the reaction. The possible mechanism is discussed.
下载: