Beyond Benign

Lead Teacher Blog

Raksmey Derival

How can I engage my high school chemistry students at the start of the year while introducing green chemistry?

How many students do you have walk into your chemistry class at the start of the year already hesitant because of chemistry’s reputation of being “boring” or “too hard”? I try to overcome these obstacles by challenging students at the start of the year with a “game” that requires creative and innovative ideas as they learn the chemistry of making glue.

Students are presented with a 26-step procedure for making glue and asked to improve the efficiency and effectiveness of the process over 3 days. My lesson expands on Writing the 12 Principles, a lesson designed to be done in one class period, which introduces many laboratory techniques students will use throughout the year, like measurements and properly mixing solutions.

During day 1, students collaborate as a class. Each student is given one step from the procedure to read aloud and perform in front of their classmates. The “original” procedure includes normal laboratory techniques alongside silly tasks, like doing 20 jumping jacks. As they work through the procedure, the students easily recognize that many of the steps are unnecessary.

That’s when I inform students that they were given a procedure with extra steps. After a review of the chemistry concepts and some guidance on which materials must be included, students revise and rewrite the procedure to make it more efficient. Day 2 allows students to test their “revised” procedures. Each item they use, and the amount of every chemical they use, is tallied to come up with a score. The lab team that has the lowest score (most efficient) while still creating a glue that works (it’s effective) is declared the winner.

After identifying the winners and debriefing what groups did to use less materials to make glue, light bulbs go off on what they can do differently to obtain a lower score. Students are told they can try the challenge again for day 3. Again, they revise the procedure and test out their now “optimized” process. This is when the students become really engaged! Students enjoy the competitive nature of the lab and start thinking really creatively! After all groups test their optimized procedures, most have successfully made glue in a much more efficient manner than day 1’s original procedure and have even demonstrated increased efficiency from day 2’s revised procedure.

This all naturally leads to a conversation about how they practiced green chemistry without even being introduced to its definition and principles! I use examples from their procedures to showcase how they prevented waste, designed for energy efficiency, increased atom economy, and supported several other green chemistry principles. Likewise, I discuss how other principles were violated during those days. I then build upon this activity by having the students rewrite the 12 principles using more student-friendly language. With this foundation set, students see that they can invent, fail, invent some more, and repeat this process until they succeed, all through the lens of green chemistry.

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