Pitching the Hot or Cold Pack

Measuring temperature change when dissolving an ionic compound.

The final project for the thermochemistry unit is the "Hot or Cold Pack Design Challenge".  This project is a good culminating event for the unit because it ties together calorimetry and energy exchange into a relevant application.  (read more about the unit here)  The project involved conducting an experiment to measure the heat exchange produced by dissolving a selection of ionic compounds, designing an original hot or cold pack based on their results and research, and then presenting their design in an "elevator pitch" to a community member.  I was so pleased with my students' collaborative work and creative ideas.  All week long, my colleagues made a point to find me at lunch to tell me how impressed they were with the presenters.  I owe all of my wonderful colleagues a huge thank you for helping make this project relevant for my kids.   I am truly grateful for my supportive colleagues at Pomfret School who will "jump right in" (our favorite catch phrase around here).

The project started in the lab with a calorimetry experiment.  I used the lab from Chemistry You Need to Know by Kelly Dieters, specifically the final chapter project for the Hot and Cold Pack chapter.  This excellent lab has clear instructions for collecting data and researching cost and safety information about sets of chemicals for hot or cold packs.  I divided the class into groups of two or three, and allowed them to chose either a hot or cold pack experiment.  Using their lab results, the students first had to choose the best system for their pack, and them make decisions about size and quantity of the chemicals to obtain the desired temperature for the pack.  They worked as a team to complete calculations and develop a hot or cold pack design.  They were asked to consider safety, cost, and their target market in their designs.  On the second day of the experiment, each group randomly picked a name out of a hat for their final presentation.  They had to make arrangements to meet with their community member outside of class to give them a 3-minute elevator pitch in the hopes of convincing them to fund their new product.

You can take a look at my project details and use them if you like this idea.  Hot and Cold Pack Design Challenge Link.   And here's the lab file I used; an adaptation of Kelly Dieter's lab from her excellent chemistry text book.  Hot and Cold Pack Experiment.

One of the key elements to a successful project is an authentic audience.  The final piece of this design challenge, presenting to a community member, is really what made the whole project a success.  The kids stepped up their game to make a good impression during their pitch.  Here are a few examples of the work they did for the pitch.

Sore No More!

Thermo Pack

One group made a commercial for their product to go along with their presentation.



The only thing I didn't like about this project is that I didn't get to see any of the pitch presentations.  I sent them out into the world with their ideas, and I heard so many enthusiastic comments from my colleagues, but I was left with a little pang in my heart because I missed out on all the action!  Maybe next year I'll have the kids practice during class so I can see them and they will get a chance to hear suggestions from the class before setting off to present to community members.  I would love to hear your feedback on this project and any suggestions for making it better next time.