The Engaged Learner

One of the reasons I like guided inquiry labs is it inspires my students to ask more 'What if...' questions. I tried a new lab this year for Stoichiometry in which the students mixed different amounts of baking soda with vinegar. A balloon was placed on the top of each test tube and the students got a great visual for the amount of gas produced.

One group finished the lab and I noticed they started to fill another balloon with a very large amount of baking soda.  When I inquired about what they were doing, they said they wanted to figure out if they could pop a balloon only using baking soda and vinegar.  With wry smile, I told them they could do it, but only if they showed, using Stoichiometry calculations, how much vinegar they would need based on the amount of baking soda they had already weighed out (28g).  

After some Internet research and a bunch of calculations later, they figured out they needed nearly 400mL (for the non-chemistry folks, that's A LOT) which is more than would fit inside their 25 mL test tube.  I happen to have a giant test tube and the experiment was off.

Here is what the face of an engaged learner looks like:

The balloon didn't pop, but it got really close.  When doing these labs, sometimes you just need to let the students' run with their ideas.  It's amazing what they will come up with and what they will learn (about science and themselves) in the process.

This is why I do the Flipped Classroom

I have been running the Flipped Classroom on and off for over a year now and while I have seen many successes, what happened yesterday really demonstrated how, when you structure it right, it really works.

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