Inspired by Tom Kuntzleman*, I started using mysteries in my chemistry curriculum this past year. The first mystery I shared with my students was burning water. While my magician skills aren't perfect, I was able to get the students asking questions and proposing hypotheses. For my IB students, it really allowed me to delve into a number of topics (e.g. combustion, intermolecular forces, polarity, density). And thus an idea was born: Using one mystery per topic. Since I teach mostly IB Chemistry, I've got 11 main topics and my work has begun to find and/or develop a mystery for each unit. It's very early in the process, but here's what I have so far:
Topic | Demo | Main Connection To Curriculum |
1: Stoichiometric Relationships | Balloon in a Bottle (discussed below) | Gas Laws |
2: Atomic Structure |
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3: Periodicity |
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4: Chemical Bonding and Structure | Burning Water (from Tom Kuntlzeman) | Intermolecular Forces |
5: Energetics/Thermochemistry |
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6: Chemical Kinetics | Clock Reaction | Effect of Concentration on Rate of Reaction |
7: Equilibrium |
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8: Acids and Bases | Sweet-Sour Chemistry (from Tom Kuntlzeman) | Acids and Indicators |
9: Redox Processes | Potato Clock | Voltaic Cells |
10: Organic Chemistry |
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11: Measurement and Data Processing (includes spectroscopy) |
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In March, I saw this tweet:
Time for some Gas Behavior! #chemchat#gaslawspic.twitter.com/ZM0aDyFb5e
— Kaleb Underwood (@kaleb_underwood) March 29, 2016
So I made my own to show some students:
Given my project of finding a mystery for each unit, I chose this mystery for Topic 1, as it includes gas laws. So I tried the demo with my Intro Chem class. I showed them the balloon and challenged them to make a replica. They were given a similar Erlenmeyer Flask and a balloon. They could handle my example, but not take it apart. The first attempt at recreating the balloon often involved putting the balloon into the flask and trying to blow it up. When this didn't work, they started asking questions and trying other things - such as putting a straw in to allow air in the flask to leave as the balloon filled the flask when it was inflated. The students got close with this general method, but could never pull off an exact replica of my balloon. Then a group got a hot plate and started heating some water in the flask, as it was obvious that there was some water inside the flask of my example. They then put the balloon on top and watched in horror as the balloon expanded more as the water heated. It took a few more rounds of trial and error before a group figured out the real method: heat a small amount of water to boiling on a hot plate, then carefully place a balloon over the top. As the water condenses, the pressure inside will decrease to the point where ambient pressure outside the balloon will push the balloon into the flask.
One of my summer tasks is to find mysteries for the other units. And so it begins!
Do you have any mysteries you've used? I'd love to hear from you. And I'll keep you posted as I develop and/or modify mysteries for the other units.
*Tom Kuntzleman's Mysteries here:
Mystery 1: Chemical Riddle
Mystery 2: Chemical Riddle 2
Mystery 3: The Sweet Side of Chemistry
Mystery 4: The Misbehaving Balloon
Mystery 5: How To Burn Water
Mystery 6: The Case of the Crushed Can