Weaving Green Principles through General Chemistry Coursework Using Systems Thinking

[ACSGCI]

Julian SilvermanBy Julian R. Silverman, Assistant Professor, Department of Science and Math, The Fashion Institute of Technology, New York, NY

How can scientists and educators meaningfully connect the United Nations Sustainable Development Goals (SDGs) with the Principles of Green Chemistry? This is a question Jessica D’eon and I tackled when we agreed to create a teaching module on stoichiometry for an introductory chemistry course. Our idea was to have students discuss the human health and environmental impacts of incomplete combustion by exploring reaction efficiency and yield.

There are so many great ways to teach balancing chemical equations, relating reactants and products, and evaluating the effects of combustion reactions. To structure our module, we followed a systems thinking approach and incorporated systems thinking activities so that students can expand the boundaries of the chemical systems we explore. This allows them to better evaluate changes to and impacts across a system, thus spurring them to think critically and address complex problems such as which route to a fuel is the most efficient?

Systems Thinking and Green Principles

Systems thinking is an increasingly popular paradigm across disciplines and in the classroom and it pairs well with the process of backward design used in curriculum development. By first identifying our main goals as learning objectives, we work backward to connect these both to the activities students will do, and the assessments we design. As part of the Module Development Program sponsored by the American Chemical Society Green Chemistry Institute (GCI), we worked alongside other instructors developing modules for General and Organic Chemistry and were able to share ideas with other development teams and learn from their efforts.

Learning objectives are the throughlines of the module, connecting lectures, activities, assignments, and assessments. These are mapped to green chemistry principles and SDGs using a Systems-Oriented Concept Map Extension (SOCME) which highlights the relationships between the required content and meaningful contexts (Figure 1). The next part we found to be the most difficult. There are so many things we wanted to say about the topics on our map, but to remain focused and avoid overwhelming students, we had to set boundaries between what topics we would and would not cover. Just as we ask our students to broaden the boundaries of the systems they investigate, it’s important that educators have a clear understanding of what is in a module (e.g., material efficiency) and what is left aside to be addressed later (e.g., energy efficiency). These defined boundaries help make a cohesive module, they are also structured to allow students to achieve learning objectives and connect them to personal interests and real-world events (e.g., indoor air pollution and climate change).

Figure 1. Example of a drafte S.O.C.M.E. for our Reaction Efficiency Module connecting Green Chemistry Principles and U.N. Sustainable Development Goal #7

Connecting Atom Economy and SDG#7 Clean Energy

Our module focused on relating the green principle of atom economy, or material efficiency, to SDG #7 (affordable and clean energy) by comparing and exploring different efficiency metrics. This allows students to assess reactions from multiple perspectives and include reagents beyond reactants (such as solvents and catalysts) in their considerations. Yield (the ratio of the actual mass of a product to the theoretical mass of a product) is commonly taught as a way to assess reaction completion. Related green chemistry metrics such as process mass efficiency (PME) include all of the chemical inputs in the calculations (Figure 2). As students compare the yield and PME of a transformation, they are broadening the boundaries of the chemical systems they investigate and learn to evaluate complex systems.

Figure 2. Comparison of metrics for reaction efficiency highlighting the more holistic nature of efficiency metrics compared to yeild

Next Steps and Future Modules

In the module described above, we focused on material efficiency so that later in the course (after thermochemistry), students can incorporate energy efficiency, a separate but complementary green chemistry principle. By comparing yields to PME, students are better able to understand certain practicalities of producing fuels from natural and petroleum-based resources. Though a reaction may have a high yield of desired product, it may produce many different byproducts, side-products, or co-products, all of which are components of the broader system.

While our module was designed to be flexible enough to be taught in a 20-student private liberal arts classroom or in a 600-person course at a research-focused institution, the module components are provided as suggested guidelines for educators and don’t comprise a rigid, fixed curriculum. Individual educators are welcome to adapt it to suit their needs.

As we embark on our second module focused on phase changes and intermolecular forces, I look forward to thinking systematically about how we teach core chemistry concepts while incorporating green and sustainable chemistry. Through the development process, I have realized that sustainable science and systematic design work cooperatively to educate the next generation of chemists. I hope you take part in using the resources created by me and my colleagues to expand the boundaries of the chemistry we teach and study.