摘要
用电化学方法研究了Ａｇ＋－Ｃｅ（ＳＯ４）２－ＫＢｒＯ３－ＣＨ２（ＣＯＯＨ）２－Ｈ２ＳＯ４化学振荡反应动力学．考察不同［Ａｇ＋］对振荡反应曲线的影响时发现，若体系中含有痕量Ａｇ＋时，则对振荡曲线产生显著影响，不同［Ａｇ＋］与振荡周期ｔｐ有良好的线性关系，线性范围为２×１０－７～１．８×１０－５ｍｏｌ·Ｌ－１，是一重现性好，灵敏度高，操作条件简单的动力学分析测试体系，升高温度可缩短反应的振荡周期ｔｐ，将ｌｎ１／ｔ，对１／Ｔ作图符合阿累尼乌斯线性关系，振荡周期ｔｐ的表观活化参数Ｅ＇ｐ＝６７．５１ｋＪ·ｍｏｌ－１，与未加Ａｇ＋的ＢＺ振荡周期表观活化参数Ｅ＇ｐ＝５８．４９ｋＪ·ｍｏｌ－１相比较可知，Ａｇ＋可使振荡周期表观活化参数增加．最后本文还对Ａｇ＋参与下的ＢＺ振荡反应体系的可能机理进行了探讨，提出Ａｇ＋可起“溴离子缓冲泵”的作用机理．
The chemical kinetics of Ag+-Ce (SO4)2-KBrO3-CH2 (COOH)2-H2SO4 scillatory reaction was studied by electrochemical method. The effect of different[Ag+] on the oscillating curve shows that if there is trace amount of Ag+ existing in system, it can cause a marked effect on the oscillating curve,the oscillatory period tp has very good linear relationship with [Ag+],the linear range is 2×10-7～1.8×10-5 mol·L-1, it is a kinetic analytical determination system of reappear good, sensitivity high and operating condition simple. The osillatory period tp will reduce when the temperature is increased, the figure of in 1/tp against 1/T conforms to the Arrhenius linear relationship, comparison of the apparent activityparameter (E'p=67. 51 kJ·mol-1 )of oscillatory period with the apparent activity parameter(Ep=58. 49 kJ·mol-1)of BZ osillatory period without Ag+ shows that Ag+ can cause the apparels activity paratemter of period to increase. In the end, the possible mechanism of BZ oscillatory reaction system with Ag+ was discused. We propose that Ag+ act as 'the buffer pump of Br- '.
出处
《武汉大学学报（自然科学版）》
CSCD
1994年第2期100-104,共5页
Journal of Wuhan University(Natural Science Edition)
关键词
振荡反应
银离子
动力学
催化剂
oscillatory reaction, Ag+ determination, mechanism
