The Final Two Resources from the 2018 AACT AP Chemistry Content Writing Team

This past summer AACT hosted an AP Chemistry Content Writing Team to create AP chemistry focused teaching resources for our High School Classroom Resource Library. The four teachers chosen focused on creating teaching resources directly related to the Learning Objectives for the topics of equilibrium, intermolecular forces, photoelectron spectroscopy, Coulomb’s Law, electrolysis, reaction mechanisms, and kinetics. This week we are publishing the last two resources from our content team.

Exploration of Electrolytic Cells

Ryan Johnson, a teacher at Doherty High School in Colorado Springs, Colorado focused on Big Idea 3 for his second lesson, specifically Learning Objectives 3.12 and 3.12. In his lesson plan, Exploration of Electrolytic Cells, students build several electrolytic cells, discuss and diagram them, and use qualitative and quantitative analysis of the results of the electrolysis of potassium iodide. After completion of the lab activity, students apply their understanding of the topic to released AP Chemistry exam-level questions.

The first day of the lesson is designed as a review of electrochemical systems and electrolysis, with the students building a simple electrochemical cell, followed by electrochemistry practice problems to aid students in their knowledge of electrochemistry stoichiometry and balancing oxidation/reduction reactions. This activity is a fun and simple way for students to observe electroplating in action, by using copper and zinc electrodes and a power source to plate the copper with zinc.

Day two of the lesson is an exploration of the electrolysis of solutions, using the electrolysis of potassium iodide to produce elemental iodine and explore the chemistry involved at both electrodes. This setup is more involved, and will likely take a full class period. Students run their electrolysis until the products are visible, recording observations and using them to inform their conclusions on the student handout. A summative assessment using Free Response Question 2 from the 2013 AP Chemistry Exam is included to use at the end of this lesson.

Reaction Mechanisms

Melissa Hemling, a teacher at Beaver Dam High School in Beaver Dam, Wisconsin concentrated on Learning Objectives 4.4, 4.5, 4.6, 4.7, and 4.8 for her second lesson plan, Reaction Mechanisms. The lesson uses three activities to help students explore reaction mechanisms and their connection to rate laws and energy profile graphs. By the end of this lesson, students should be able to explain the importance of the rate-determining steps and catalysts, identify key parts of a reaction mechanism, and justify the validity of a proposed mechanism.

The lesson begins with the Hungry, Hungry Hippo Collisions activity, which allows students to use a common childhood game to understand the concept of collision theory. The activity requires that students understand the basics of chemical reactions and bonding, as well as reaction profile and Maxwell-Boltzmann graphs. It is written for the whole class to participate but can easily be modified depending on your resources. There is a guided inquiry student worksheet for your students to complete as they connect collision theory and reaction mechanisms to the activity.

The second activity, Kinetic Relay Race, builds off of the collision theory activity to develop the concept of the rate determining step. In it, students complete a simple relay race to model a multi-step reaction and identify the slow step. There is also a student worksheet to help them apply lessons learned from the relay race to reaction mechanisms. The final activity, Is It Valid, uses the Elephant Toothpaste demonstration to connect a real chemical reaction with a proposed mechanism to confirm validity. After completing the final student activity sheet, there are several released AP Chemistry Free Response questions included to use as a summative assessment.

We hope that you find these resources useful with your AP Chemistry classes. If you missed the AP resources from this team that were published earlier this fall, you can still access them:

• September AP Resources: Redox Titrations and Coulomb’s Law
• October AP Resources: Introduction to PES and Exploration of Intermolecular Forces
• November AP Resources: Making Connections in Kinetics, Equilibrium, and Thermochemistry and Q, K, and Le Chatelier

The two lessons in this news post are the final AP resources created by this content writing team. If you have an AP Chemistry resource that you’d like to share with the AACT community, please send it along for consideration.