用分光光度法测量碳酰肼及孔雀石绿与碳酰肼的缩合反应动力学

用分光光度法研究了(15.0～22.0) ℃温度区间，水溶液中孔雀石绿和碳酰肼的缩合反应动力学。结果表明：此反应为二级反应，对于反应物分别为一级反应，离子强度在(0.2～1.0) mol·L^-1内对该反应产生负盐效应。提出了孔雀石绿和碳酰肼的反应机理。据此机理导出的速率方程与实验结果相吻合。在此基础上提出了测量碳酰肼浓度范围在(0.02～0.5)×10^-3 mol·L^-1的分光光度法。

Determination of Carbohydrazide and Kinetics of Condensation reaction of Carbohydrazide with Malachite Green by Spectrophotometry

The kinetics of the condensation reaction of malachite green and carbohydrazide was studied by spectrophotometry in aqueous solution in the temperature range of 15.0–22.0 °C. The reaction was found to be second‐order overall, first‐order with respect to each reactant. The effect of ionic strength on the reaction has negative salt effect in the range of 0.2–1.0 mol ˙ L^–1. A mechanism of the reaction between malachite green and carbohydrazide was proposed, and the rate equation derived from the mechanism can explain all experimental observations properly. Based on this reaction, a method of determining the content of carbohydrazide in the concentration range of (0.02–0.5)×10^?3 mol · L^?1 was proposed.