卤化物对铜铝置换反应速率的影响研究

Effects of Halides on Rate of Cu-Al Replacement Reaction

从定性和定量角度探究了卤化盐对金属置换反应的催化作用,实验结果表明:卤族元素均有催化作用,Cl-催化作用最为明显;碱金属与碱土金属离子相比,碱金属条件下铜枝晶形状更为规则,观赏性更好;同时该反应速率与Cl-浓度呈正相关。通过对反应条件的摸索,实现了将铝置换铜的所谓"铜树"反应改造为能在20 min内产生明显现象的课堂演示实验,可为金属置换反应和电化学腐蚀动力学教学创设情境,培育学生证据推理和模型认知的化学核心素养。

In this study, the catalytic effect of halides on metal replacement reaction was studied qualitatively and quantitatively. The experimental results show that all halogen elements have catalytic effect, and Cl- has the most obvious catalytic effect;compared with alkaline earth metal ions, the copper tree crystal shape is more regular under alkali metal conditions, and the ornamental effect is better;at the same time, the reaction rate is positively correlated with Cl- concentration. Through the exploration of reaction conditions, the so-called "copper tree" reaction of aluminum replacement of copper is transformed into a classroom demonstration experiment which can produce obvious phenomena in 20 minutes. It can create a situation for the teaching of metal replacement reaction and electrochemical corrosion kinetics, and cultivate students’ chemical core literacy of evidence reasoning and model cognition.