摘要
针对教材中“影响盐类水解平衡的主要因素”部分的实验进行改进。确定室温下滴加了石蕊的酸性溶液在pH=5.0时发生颜色突变,根据此条件下水、氨水的电离平衡常数,定量计算并配制0.09 mol·L^(-1)的硫酸铵溶液,添加石蕊后初始颜色为紫色,通过对比加热、降温时溶液的显色变化,将铵根离子水解平衡移动的过程可视化。通过在“颜色溶液”中加入强碱弱酸盐探究双水解反应的本质,进一步验证温度、浓度对盐类水解造成的影响。实验简便快捷、效果明显,以可视化的思维过程助益学生建构完整的认知模型。
This paper improved the experiment for the main factors that affect salt hydrolysis balance in the textbook.Experiments confirmed the acid solution with litmus changed colour at pH=5.0 and room temperature.According to the ionization equilibrium constants of water and ammonia,0.09 mol·L^(-1)ammonium sulfate solution was quantitatively calculated and prepared.The initial colour of ammonium sulfate solution was purple after the addition of litmus.By comparing the colour changes during heating and cooling,the equilibrium movement process for the hydrolysis of ammonium ion was visualized.By adding strong base weak acid salt into“coloured solution”,the essence of double hydrolysis reaction was explored,and the influence of temperature and concentration on salt hydrolysis was further verified.The improved experiment was simple,quick,and effective,and the visualization of the experiments helped students to construct a complete cognitive model.
作者
杨杰
姜建文
曾承辉
YANG Jie;JIANG Jian-Wen;ZENG Cheng-Hui(College of Chemistry and Chemical Engineering,Jiangxi Normal University,Nanchang 330022,China)
出处
《化学教育（中英文）》
CAS
北大核心
2023年第3期104-110,共7页
Chinese Journal of Chemical Education
基金
江西省教育科学“十三五”规划课题“‘双一流’背景下化学综合知识体系建构及创新性人才的培养”(课题编号:19YB018)
江西师范大学教改课题“‘双一流’背景下创新性和高水平化学人才培养体系研究”(课题编号:JXSDJG1840)。
关键词
盐类水解
思维可视化
教学实验设计
认知模型建构
hydrolysis of salts
thinking visualization
teaching experiment design
construction of cognitive model
