Submitted by Michelle Personick / Wesleyan University on Wed, 06/23/2021 - 12:08
My Notes

This is an in-class activity that I use in my advanced general chemistry course right before I start teaching about the relationship between the Bronsted acidity of cations and their hydration/hydrolysis. This is the first topic in the course (reactions of ions in aqueous solution), and we would have just spent a lecture reviewing intermolecular forces. 

The goal of the activity is to get students thinking about the types of interactions and reactions that can take place when ions are introduced to water, as well as how these interactions are influenced by properties of the ion, such as charge. In the subsequent lecture, I teach that many properties of ions in aqueous solution (hydration number, hydration energy, acidity/basicity) trend with Z2/r (where Z is charge and r is radius).

Learning Goals

This activity is meant to help students discover concepts that prepare them for a subsequent lecture. Students should be able to apply their knowledge of chemical principles from the first semester of general chemistry to come to the conclusion that physical and chemical changes can occur when ions interact with water.

Implementation Notes

I have the students work on the activity in groups and then we discuss it together at the end of class. When I used the activity I was teaching via Zoom, so I had students collaborate with their group in a Google Doc (one page per group) and I followed along while they were in their breakout rooms. I taught my class in a flipped format, so the activity is designed to take a full 50 minute class period, including introduction, group work, and full class discussion.

Time Required
40-50 minutes
Creative Commons License
Attribution, Non-Commercial, Share Alike CC BY-NC-SA