稀硝酸体系中<i>N,N</i>-二甲基羟胺与亚硝酸反应的动力学

稀硝酸体系中N,N-二甲基羟胺与亚硝酸反应的动力学

摘要: 采用分光光度法研究了0.1~0.4 mol/L稀硝酸体系中N,N-二甲基羟胺（DMHAN）与亚硝酸的反应动力学，包括硝酸浓度、亚硝酸浓度、二甲基羟胺浓度、离子强度、温度等条件的影响。稀硝酸体系中二甲基羟胺与亚硝酸反应的动力学方程为：
 -dc(HNO₂)/dt=kc^1.26(HNO₂)c^0.85(DMHAN)c^0.45(H⁺)
在20 ℃，离子强度为0.50 mol/L时，k=3.09 (mol/L)^-1.56•s^-1，E_a≈55.1 kJ/mol；反应中，亚硝酸与二甲基羟胺的表观反应计量比约为2.5∶1。

Abstract: The reaction kinetics of N,N-dimethylhydroxylammonium ion(DMHAN) with nitrous acid were studied by spectrophotometerly in 0.1-0.4 mol/L nitric acid media. Influences of temperature, ion strength, nitric acid concentration, nitrous acid concentration and DMHAN concentration were investigated. The reaction rate equation is obtained as:
 -dc(HNO₂)/dt=kc^1.26(HNO₂)c^0.85(DMHAN)c^0.45(H⁺)
The reaction rate constant and the reaction activation energy are 3.09 (mol/L)^-1.56•s^-1 and 55.1 kJ/mol at 20 ℃, μ=0.50 mol/L, respectively. The stoichiometric ratio of nitrous acid to DMHAN is observed by 2.5∶1.