手持技术探究离子浓度对沉淀溶解平衡的影响--同离子效应和盐效应

Exploring Influence of Ion Concentration on Precipitation-Dissolution Equilibrium Based on Handheld Technology: Co-Ionic Effect and Salt Effect

基于手持技术探究同离子效应和盐效应对氢氧化镁沉淀溶解平衡的影响,通过将氢氧化镁水溶液的宏观变化与实验曲线相结合,进而推测微观的反应原理,最后再以可逆方程式等符号形式进行表征,从而提高学生的证据推理能力,实现“四重表征”思维模式的培养,为相关的教学提供素材。此外,针对实验过程中的“异常”现象,引导学生进行猜想假设、设计实验方案、开展实验探究等活动,发展学生的批判质疑思维与创新精神,提高解决冲突与灵活思维的能力,落实“科学探究”与“科学态度”等核心素养的培养。

Based on handheld technology, the influence of co-ionic effect and salt effect on precipitation and dissolution equilibrium of Mg(OH)2were explored. By combining the macroscopic change of Mg(OH)2aqueous solution with the experimental curve, the microcosmic reaction principle was deduced and characterized by the reversible equation and other symbolic forms. Thus, students’ evidential reasoning ability and “quadruple representation” thinking mode were cultivated, and provided new materials for relevant teaching. In addition, in view of the “abnormal” phenomenon in the experiment process, students were guided to make assumptions, design experimental schemes and other activities. These exploration activities not only developed students’ critical questioning thinking, innovative spirit, conflict resolution and flexible thinking abilities, but also implemented the cultivation of core literacy of “scientific inquiry” and “scientific attitude”.