硝酸介质中尿素与HNO_2的反应动力学  

Reaction Kinetics of Urea With Nitrous Acid in Nitric Acid Medium

作　　者：张译方[1] 

机构地区：[1]中国广州分析测试中心,广东省化学危害应急检测技术重点实验室,广东广州510000

出　　处：《广东化工》2017年第7期117-119,共3页Guangdong Chemical Industry

基　　金：[基金项目]可降解塑料检测与评价技术服务平台建设

摘　　要：在硝酸介质中,采用分光光度法研究尿素(Urea)与亚硝酸(HNO_2)的反应。通过考察不同浓度的尿素、不同溶液酸度、离子强度和温度等因素对反应过程的影响,得到硝酸介质中Urea和HNO_2的反应动力学速率方程为,-dc(HNO_2)/dt=kc(HNO_2)c^(0.90)(Urea)c^(0.46)(H+),当t=20℃、c(NO_3^-)=2.00 mol/L时,反应速率常数k=0.15±0.01(mol/L)^(-1.36)s^(-1),反应活化能E_a=(34.4±0.2)kJ/mol,研究结果表明,在硝酸介质中,尿素与HNO_2能快速反应。提高尿素浓度、溶液的酸度和温度均有利于亚硝酸的还原。而离子强度的变化对反应速率影响不大。The oxidation of Urea by nitrous acid in nitric acid medium as well as the effects of c（H＋）, c（Urea）, iota strength and temperature on tile reaction were studied. The rate equation in nitric acid was determined as follows： -dc（HNO2）/dt=kc（HNO2）c^0.90（Urea）c^0.46（H＋）, where k=0.15±0.01（mol/L）^-1.36s^-1 when the temperature is 20 ℃ and the ion strength is 2.00 tool/L, with an activation energy about of （34.4±0.2） kJ/mol. The result indicates that the oxidation of Urea with nitrous acid is fast. The increase in the concentration of Urea and the acidity or NO3 can speed up the reduction of nitrous acid.

关 键 词：尿素 亚硝酸 反应动力学 

分 类 号：TQ[化学工程]