热动力学研究的线性拟合法(Ⅰ)——简单级数化学反应

SPECTROPHOTOMETRIC STUDY ON SYSTEM OF Mn(Ⅱ) Op 5 Br PADAP

在热动力学理论的基础上，导出了简单级数反应的线性拟合法．应用这种方法研究了乙酸乙酯在纯水中、丙酸乙酯在“７０％”乙醇－水混合溶剂中、丁酸乙酯在“８５％”乙醇－水混合溶剂中皂化反应的热动力学．实验测得的速率常数与文献值相符合．

The formation condition and stability of 2 (5 bromo 2 pyridylazo) 5 diethylaminophenol(5 Br PADAP) with Mn(Ⅱ) in the presence of polyethylene glycol monooctylphenyl ether (Op) are investigated by spectrophotometry.Results show that a stable red complex is found in the medium of pH9.4.Beer′s Law is obeyed for Mn(Ⅱ) in the range of (0～1)mg/L.The molar absorptivity at 566nm is 1.06×10 5.The molar ratio of Mn(Ⅱ) to reagent in the complex is 1∶2.The relative standard deviation is less than 3.0% (6 determinations).The recovery of standard addition is 96%～98%.The method has been applied to the determination of Mn(Ⅱ) in tea with satisfactory results.