For the first lesson of chapter 16, students were formally introduced to acids and bases via a lab. We began class with the Lesson 84 PowerPoint which included a starter question helping students connect acid/base chemistry with the biology of heartburn. After learning about indicators, chemical solutions that change color in response to changes in pH, we reviewed the Lesson 84 worksheet. For Part 1, students were instructed to number the nine solutions in order, with the number on the worksheet corresponding to one of nine numbered flasks containing the indicated solution. An image of the lab setup is shown below:
After students complete the lab portion of Part 1, they were instructed to return to their seats to complete the Part 1 analysis questions. We will share out results as a class, and if time permits, conduct Part 2 as a teacher-led demonstration.
Example of student results with indicators – samples are arranged #1-9 in rows A and B, with cabbage juice indicator in row A and universal indicator in row B.
Results from the teacher-led demonstration for Part 2 are shown below: