Generating an Evidence-Based Guide to Scaffolding Sodium Chloride Dissolution Using the VisChem Approach

Aqueous solutions have proved to be a challenging topic for chemistry students at all levels. An understanding of what is happening at the molecular level in aqueous processes such as dissolution is key to understanding the macroscopic properties of the system as well as to communicating fluently with chemical symbols. In this study, we examined the storyboards of 28 high school students in the United States who participated in a series of lessons employing the VisChem Approach that addressed the topics of liquid water, solid sodium chloride, and finally sodium chloride dissolution in water over the course of a year. Results of the study indicate that the VisChem Approach is effective in helping students gain knowledge about aqueous systems. Using the results of this study, we developed a teaching guide for scaffolding learning about the three topics, including detailed knowledge targets and recommended teaching moves for each of the three lessons.