My Honors Chemistry class is just the perfect combination of students: energetic, open-minded, willing to try, outside-the-box thinkers. I have been including more inquiry labs in their units, something I was definitely lacking in previous attempts at this. In the one they are currently working (Gas Laws), I asked them to create a lab that measures the amount of CO2 produced in the reaction of Baking Soda and Vinegar and compare that to the theoretical value that should be produced. We are getting a lot of great ideas on how to measure the gas (measuring the volume of a balloon, water displacement by immersing the balloon in water, water displacement by bubbling the gas through water), none of which I suggested to them, all of which have had different results.
Since the materials where already out for the lab, I did the following demo for a group of the students trying to get them to explain it with gas laws.
After they came up with a good explanation, another student chimed in with “So can we do the opposite to get the balloon out? Could we heat the flask and see if it inflates the balloon above the flask?” Well, who am I to stop them? So they set everything up and sure enough it pushes the balloon back out. Unfortunately, because the mouth of the balloon can’t hold on tight enough the balloon pops off.
So the same student says, “What if we blow the balloon up a little first, put it on the flask, and then heat it? Could we get it big enough to pop the balloon?” I stepped back, took a seat on my stool and got out of their way. In hindsight, I wish I had my video camera ready. The balloon got pretty big, but eventually the gas in the balloon hits an equilibrium point and the water condenses. The balloon never popped because the gas pressure doesn’t get high enough.
Now the door has been opened. Today the students rushed in trying to do it again with a bigger flask and more water. Then they did it with the same amount of water, but a smaller flask. Then they tried with heating the baking soda and vinegar lab. Nothing popped the balloon. Now, while my lab benches are now white with baking soda and the room has a severe vinegar smell, if I had to do it all over again I would. It was the greatest 2 days of unadulterated learning I have had in my career.
This is why I do the Flipped Classroom