S_2O_3^(2-)在强酸中的水解动力学及反应机理研究  

Study on Hydrolysis Kinetics and Reaction Mechanism of Thiosulfate Under Strong Acidic Condition

作　　者：陆永超 路瑶 高庆宇[3] 

机构地区：[1]徐州医科大学公共教育学院,江苏徐州221004 [2]中国矿业大学现代分析与计算中心,江苏徐州221116 [3]中国矿业大学化工学院,江苏徐州221116

出　　处：《辽宁化工》2017年第12期1162-1165,共4页Liaoning Chemical Industry

基　　金：徐州医科大学优秀人才科研启动基金项目;项目号:D2015020

摘　　要：采用毛细管电泳对硫代硫酸根离子S_2O_3^(2-)在强酸性条件下的水解反应动力学进行了研究。反应体系中检测到多种含硫物种,包括硫S_8、HSO_3^-、HS-、HS_2O_3^-、HS_n^-、HS_nO_3^-和S_nO_6^(2-)等。动力学分析表明,在溶液pH 1.20~2.50范围内,S_2O_3^(2-)的水解反应对于S_2O_3^(2-)的浓度为1级反应,而受pH的影响却不明显,水解速率常数为8.8×10^(-4) min^(-1)。提出17步反应机理,其中揭示了HS_n^-和HS_nO_3^-是产生S_8和S_nO_6^(2-)的主要途径。The hydrolysis reaction kinetics of S2O3^2- under strong acidic condition was studied by using capillary electrophoresis.Several sulfur-containing species were detected,such as colloid sulfur（S8）,bisulfite（HSO3^-）,hydrogen sulfide（HS^-）,bithiosulfate（HS2O3^-）,polysulfides（HSn^-,n≥3） and polythionates（SnO6^2-,n≥3）.It was found that the hydrolysis of S2O3^2- was first order with respect to [S2O3^2- ] within the pH range between 1.20 and 2.50; meanwhile,this reaction kinetic was independent of pH.The reaction rate constant was 8.8×10^-4 min^-1.A 17-step mechanism was proposed with SnO6^2-,HSn^- and HSnO3^- as the main intermadiates.It was also shown that HSn^- and HSnO3^- were the main source for the formation of S8 and SnO6^2-.

关 键 词：硫代硫酸根离子 酸性 水解 动力学 

分 类 号：TQ013[化学工程]