高氯酸介质中单甲基肼与亚硝酸的反应动力学

Reaction Kinetics of Monomethylhydrazine With Nitrous Acid in Perchloric Acid Solution

用分光光度法研究了高氯酸介质中单甲基肼(MMH)与亚硝酸(HNO2)的反应,建立了单甲基肼与亚硝酸的反应速率方程式。高氯酸介质中HNO2和MMH反应的速率方程如下:-dc(HNO2)/dt=kc(H+)0.9c(MMH)1.1c(HNO2)。温度4.5℃,c0(Cl O4-)=0.50 mol/L时,反应速率常数k=(46.0±2.7)L2/(mol2.s),该反应的活化能Ea=(42.4±0.1)kJ/mol。以上研究结果表明,在高氯酸介质中,单甲基肼与亚硝酸能很快反应,提高酸度、增大单甲基肼浓度均有利于亚硝酸的还原。

The oxidation of monomethylhydrazine（MMH） by nitrous acid was researched in perchloric acid solution with spectrophotometry. The rate equation has been determined as follows.-dc（HNO2）/dt=kc（H^＋）^0.9c（MMH）^1.1c（HNO2）, k is （46.0±2.7）L^2/（mol^2·s） with the initial perchlorate concentration of 0.50 mol/L at the temperature of 4.5 ℃. The corresponding activation energy of the reaction is （42.4±0. 1） kJ/mol. The results indicate that oxidation of mono-methylhydrazine（MMH） by nitrous acid is fast. The higher concentration of MMH can accelerate the reduction process of nitrous acid. Higher acidity can also speed up the reduction of nitrous acid.