碱性条件下Sn(Ⅱ)还原TcO_4^-的动力学研究  

Reduction Kinetics of TcO_4^- by Sn(Ⅱ) in Basic Medium

作　　者：刘德军[1] 范显华[1] 姚军[1] 

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413

出　　处：《核化学与放射化学》2005年第2期70-74,共5页Journal of Nuclear and Radiochemistry

摘　　要：为了解在碱性介质中Sn(Ⅱ)还原TcO-4的动力学性质,用萃取法和液闪计数法研究了TcO-4,Sn(Ⅱ),OH-浓度和温度对Sn(Ⅱ)还原TcO-4反应速率的影响。结果表明,TcO-4被Sn(Ⅱ)还原为Tc(Ⅳ),Sn(Ⅱ)与TcO-4发生氧化还原反应的计量式可表示为:3Sn(Ⅱ)+2Tc(Ⅶ)3Sn(Ⅳ)+2Tc(Ⅳ)。在碱性介质中,Sn(Ⅱ)还原TcO-4的化学反应速率方程为:-dc(TcO-4)/dt=kc(TcO-4)c-0.478(OH-)c0.629(Sn(Ⅱ)),反应的活化能Ea=29.08kJ/mol。The reduction kinetics of TcO_4^-by Sn(Ⅱ) in basic medium is studied. The influence of the concentrations of TcO_4, Sn(Ⅱ), OH- and temperature on the reaction rate is investigated by extraction separation and liquid scintillation measurement for TcO_4 concentration. Experimental results show that TcO_4 is reduced to Tc(Ⅳ) by Sn(Ⅱ) and the stoichiometry of the reduction can be expressed as: 3Sn(Ⅱ)+2Tc(Ⅶ)3Sn(Ⅳ)+2Tc(Ⅳ). The reaction rate expression is obtained as: -dc(TcO_4)/dt=kc(TcO_4)c -0.478 (OH-)c 0.629 (Sn(Ⅱ)). The activation energy of the reaction is about 29.08 kJ/mol.

关 键 词：TcO4^- Sn(Ⅱ) 萃取 化学动力学 

分 类 号：O611.3[理学—无机化学] O614.712[理学—化学]