The Ideal Hot Beverage Container: PBL in AP Chemistry

As part of a joint effort between my Cohort action plan and my school-based action plan, I recently set my grade 12 AP Chemistry class a task:

How Might We design the ideal hot beverage container?

This was a project-based learning (PBL) activity to kick off the thermodynamics unit. For those who are unfamiliar, PBL is an alternative teaching style. Traditionally, we disseminate information first, have students learn it, then assign problems that use these skills. With PBL, a problem is assigned first – and students DO NOT (yet) have the required knowledge or skills to fully answer it. As they struggle through, and as teachable moments arise, the teacher fills in the knowledge gaps so that students can properly tackle the problem.

what is pbl


I was up-front with my students at the start: I wasn’t sure how long this activity would last – 1 day or 3 weeks – or how it would be assessed. But I wanted all of us to step outside our collective comfort zones and try something new. I had students work in groups of 3 or 4. They were pretty well engaged, so I pressed onward. Each day I introduced a leading design question, and waited for a teachable moment to help them fill in the gaps. For example, “Determine the capacity of the beverage container, what material it is made of and its mass.” Or, “What will be the effect of adding milk to the hot beverage?” I purposefully kept these questions fairly vague, so that they would need to decide things like how much milk should be added. Sometimes it took multiple days to come to a reasonable answer to one of these questions, and I accepted that.

The teachable moments arrived right on schedule. First, it was heat capacity, open/closed/isolated systems, and the laws of thermodynamics. Then, it was calculations for the 2nd law of Thermodynamics. Then, enthalpy and solvation. Finally, calorimetry. I covered nearly an entire chapter from the text book in a reasonable amount of time, with an authentic learning task that kept students engaged for nearly 3 weeks. I even got a lab in! (Students had to determine the enthalpy of solution of sugar – the temperature change due to sugar dissolving in water)

Just before the Christmas break, I asked students to collect their work, make sure it was neat, and submit for grading.

My biggest fear at the start was that this would be a waste of time and I would have to re-teach the thermodynamics concepts traditionally at the end. While it remains to be seen if that will be necessary or not, I think the students mostly enjoyed the experience. It’s definitely something I will do again.

Have you tried anything like this? Got any ideas for what other PBL-style projects I could try in grade 12 chemistry or grade 10 science? Post in the comments below!

9 thoughts on “The Ideal Hot Beverage Container: PBL in AP Chemistry

  1. Yes Jason! This is so awesome. I love how your experiments last year with building student’s resilience in problem solving have now dovetailed into this project where you’re giving students a challenge and the problem solving becomes necessary in order to succeed in the challenge.

    A couple questions for you:
    What framework did you use for them to work through the design challenge? Almost all of my units in Green Industries class were project-based, and over the years I found that the more I structured the thinking/ideation process for them, the better their ideas became. You can use a lot of the same structures that we use at Cohort 21 to help them come up with ideas.

    In terms of assessment: Have you considered assessing their work throughout the process, not just at the end? I found that at each stage of the design process (empathize/define – ideate – prototype – test – reflect) there is opportunity for assessment for, as, and of learning. It really brings that feedback loop to life.

    Let’s chat more about this next week!


  2. Hey @lmcbeth thanks for your feedback. It was definitely a nice next-step to take with my students from last year and build upon their Grit.

    Since it was a bit of a wait-and-see, feel-it-out situation, I didn’t have a proper protocol planned. It was a lot of free thinking, brainstorming, and conversations (both between group members, and me visiting the groups one at a time). I tried to provide good constructive feedback, reasonable next steps, and point out various things to think about. Next time I will try to structure the activity a little better, but I still got some positive outcomes.

    Looking forward to discussing it with you in person next week!

    1. I love how you embraced the ambiguity of it and just dove in! It took me about 5 years of testing (and failing) to get the right balance of student-led, but teacher-facilitated project for my students. I’m sure that your students appreciated your open mind and flexibility! I’d love to hear about what they invented too!

  3. Thanks for sharing Jason! This sounds like an awesome PBL sequence for grade 12 chemistry. I would love to see an example of a student’s final submission!!

    I’m curious about how your structured the “teachable moments” that you referenced. Were they directed at the whole class, or individual groups? Did you use a pre-made Powerpoint lesson, or an impromptu chalk-and-talk? Did students take notes?

    I am always apprehensive to do open-ended projects, because I worry that I will either over-direct leading to students missing the real benefit of inquiry, or that I won’t be directive enough and they will have a good experience but not understand the scope of the content for our final exam. I would love to hear more about your experience.

    1. Thanks @jhowell,
      Teachable moments were always impromptu, in the chalk-and-talk style (the style I use most often for all lessons), and directed to the whole class. Most students took notes – I have a pretty diligent class. I will try to bring copies of student work next week!

      It is definitely a challenge to hit the sweet spot between over-directing and under-directing, but it was a risk I was willing to take here. I always say that I’ll try anything once! Hopefully the students got enough scope of content out of it, but I won’t know for sure until the next test.

  4. Hi @jbornstein,

    Great post about your experiences with PBL. I am working in incorporating elements of PBL into my courses too. It would be great to chat about it at the next F2F next week. I have had similar observations of my attempts so far – providing broad questions really helps to expand students’ perspective and prevents them giving the obvious answers. I have found it really enriching so far. It is scary to give over some of the control to students, but has produced much more interesting results.

    I will be interested to hear about your other plans, thanks again,

  5. Yes @jbornstein! I love this PBL and would love to see some of your students’ work as @jhowell mentioned too!

    I love seeing your journey from last year to this one. Isn’t it exhilarating to hand over some of the responsibility and allow students to work hard and say smart things, instead of us?!

    I wonder if @sregli might chime in here to offer some insight on the chemistry front, or @maragona! I wonder how she is using PearDeck these days? Did you hear that Peardeck is now an Add-On for Slides?

    I am curious to know what was challenging and tricky in doing all of this? It’s good to share this for those who are just jumping in.

    Thanks for sharing, you’re a model for us all!

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