PBL: Teaching Chemistry in Context

By | July 18, 2010

While teaching at my first school, I had an opportunity to pilot two textbook/curriculums for chemistry: Active Chemistry and Chemistry You Need to Know. They are fairly similar: rather than introducing topics in an order that only makes sense to those of us who know what’s going on, topics are introduced on a “need to know” basis.

In Chemistry You Need to Know (CYNTK), students are hooked in to chapter two with a traditional Alka-Seltzer cannon. With an ultimate goal of learning how to speed up the reaction, students learn nomenclature, properties of acids and bases, chemical reactions, balancing equations, and collision theory. Active Chemistry (AC) takes an active learning, PBL approach. For example, students are tasked with building amusement park rides based on the digestive system, aand complete a series of hands-on activities about kinetics, enzymes, acids and bases, and gas laws.

While I wasn’t sold on either text, both offered something that I found valuable. CYNTK emphasizes experimental design and inquiry labs. AC offers contexts that “non-sciencey” students may be interested in, and allows them to develop the criteria upon which they will be assessed. Unlike the American Chemical Society’s texts Chemistry in the Community and Chemistry in Context, both offer interesting contexts for learning chemistry beyond environmental issues.

Both of these new texts are moving in the right direction: from science as a series of disconnected ideas to a living, breathing process. But we certainly don’t need textbooks to define contexts for us, or our students.

I’ve been thinking a lot about my advanced curriculum for next year. Though I am not constrained by the AP curriculum, and despite the fact that I inject some pretty cool labs and projects, for the most part, I tend to cover topics in the same order:

Q1 Atoms, Molecules, Ions
Chemical Reactions & Stoichiometry
Atomic Structure & Quantum Theory
Q2 Periodicity
Q3 Equilibrium
Acids & Bases
Q4 Electrochemistry
Nuclear Chemistry
Organic Chemistry

Tried and true, most colleges teach in a similar fashion. Virtually all textbooks are organized in this way. It is ideal for a teacher-centered course, to jump from macro behavior of compounds and elements in chemical reactions to internal structure of atom and bonding, back to macroscopic kinetics and equilibrium when you don’t have time to explain why. When your only context is tradition, science becomes as dead as the 1000+ sheets of glossy paper the text is printed on.

So, my challenge is to approach the same advanced topics in the context of a task, project, or problem. Rather than rushing from topic to topic, allow students to set their own pace, diving into the topics they find relevant to address the task, and nothing more.

Two undeveloped ideas I jotted down yesterday:

Task A chemical company has obtained a strange compound as a side product of a synthesis that may be useful for another reaction. Your class has been hired to identify the compound, analyze its physical properties and reactivity and find a simple method of synthesizing it.
Topics Nomenclature, complex ions, stoichiometry, hydration, chemical reactions, solubility, solutions, titration, thermochemistry, pH, qualitative analysis
Task A pharmaceutical company has hired your class to investigate the optimal conditions for a biological enzyme.
Topics Organic side groups, intermolecular forces, molecular shape, kinetics, acids & bases, equilibrium, buffers, factors affecting protein shape (temp, pH, ionic

What contexts can we use to not only keep chemistry “alive” for our students, but shape our curriculum?


Alex Rosenwald (@arosey) on July 19, 2010 at 5:27 am.

Ooooh, this looks fun! Can I play?

Task: A consumer advocacy group has hired your class to test the claims of so-called “heavy duty” aluminum foils vs. regular brands. Your job is to develop a ranking system of recommendations for the foil samples, and provide a report explaining your reasoning.

Topics: Density, atoms, moles, unit conversions, introduction to lab procedures

My Analytical Chemistry II class in college was organized so that we were in “companies” of 3-4 students each, with clearly defined roles that we rotated through as the semester progressed. The “manager” was responsible for the vision for how to attack the problem at hand, as well as having to make the final presentation to the “CEO” (aka the professor). The “chemist” was responsible for prepping all the necessary solutions for the project, as well as helping the manager develop a plan for attacking the problem. The “instrumentalist” was responsible for learning how to use the “instrument of the week”, teaching the rest of the company, and assist while everyone took a turn running samples through the instrument. Looking back on it, it was an amazing example of PBL & cooperative learning, done on an extremely high level AND on a weekly basis.


Ms. Bethea on July 19, 2010 at 10:19 am.

I like it!

That analytical course sounds fantastic! I think this could be easily adapted for high school (jigsaw).


beth chase on July 24, 2010 at 5:17 pm.

Hey, this looks awesome. I am a science teacher in Texas. I am an ecologist/naturalist by training (long ago) who has recently been assigned to teach a Texas course called Integrated Physics and Chemistry. (I was previously teaching biology.) We begin with Chem. which happens to be, by far, my weakest subject. I would like to email with you to pick your brain for ideas. I have good support through the teachers at my school but many of them follow convention and I am looking for successful, positive deviants to learn from so that I can give my kids better that “convention”.

At first I was reluctant and apprehensive about this new assignment since I am not good at chemistry. However, because I am an environmental geek by training, I am actually becoming more excited because I see a lot of opportunities to make use of environmental issues to teach this course.

I would be most grateful if you would be willing to email me at the addy included above so I could ask some questions.

Meanwhile, I am going wander through your blog.


T.J. Edwards on June 27, 2011 at 6:39 pm.

I recently found your blog and have loved perusing through your various topics. Kudos to you for going beyond status quo to make science teaching much more relevant for 21st century learners. I’m a new chem and bio teacher at a school that stresses 21st century learning and design thinking. Your site has been a great resource for me!

As for the question at hand (albeit a post from last year), I’d suggest you check out the lessons on http://www.BeyondBenign.org. This is a group that seeks to shout the gospel of “Green Chemistry” from the mountain tops. Their lessons focus on 12 principles of green chemistry (such as limiting waste, using renewable and safe reagents, etc), but all are very relevant and creative PBL type lessons. One in particular – you have to link under the Biotechnology tab – approaches genetics from a “we hired your class to…” perspective like you suggested above.

Hope it helps… and THANK YOU for the wealth of information you are sharing.


AHCline on August 20, 2012 at 9:33 pm.

Thanks so much for posting your review of these different types of curricula. I too am a marine biology/environmental science focused teacher that is now teaching chemistry. I am a very interdisciplinary and thematic teacher and am trying to write a course that will be taught to high school students that have some sort of learning disability i.e. dyslexia. I would like to integrate design thinking into my curricula as well as one of the previous commenters stated.
If its possible, I would love to see a syllabus or parts of a curriculum that you ended up teaching. I really liked the scenario based challenges you “jotted down” at the end of your post. Did they work out? What would you have changed?
Id love to hear more and test any of your ideas in my classroom.
Thanks so much for posting and I hope to hear more soon!
Best – amy


Sabitu abdulmaliki on April 21, 2013 at 10:37 am.

Waw! This is realy intresting i am also a masters student in science education wanted to carry my research on pbl strategy in separation tech. Chemistry.i wll be happy if u can post me a samle lesson plan. Thanks


Terri olix on January 15, 2015 at 1:29 pm.

I have been trying to approach these topics in a similar way you are and then differentiate the tasks by the content level researched and which aspect of the task the students take. This is my first year teaching chemistry and I wondered if anyone knew of any pre-made resources that I can access as with 5 preps my time and knowledge at this point is limited.


Dolly domingo on June 27, 2016 at 1:46 am.

I have fun reading your topics. I am also teaching science. For sure, the topics/ ideas will be of great use in my class.



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