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How do you teach "entropy" to high school students?

I was recently drawn to an article published ASAP in JCE entitled Application of the Second Law of Thermodynamics To Explain the Working of Toys. Erick Castellon wrote the article highlighting the use of three toys that are used to help students develop an understanding of the second law of thermodynamics and entropy by having them observe the working of the toys and the energy transfers that occur while playing with them. I already had two of the toys, the radiometer and the drinking bird. I ordered the stirling engine from the link provided in the supporting information. As I waited for the stirling engine to arrive from Japan (which was only a few days) I attempted to write an activity to guide my students to conceptual understanding as they worked with the toys.

Floating Squares

I was looking for a new demonstration to initiate a discussion about polarity and related properties to use as part of an exam review. I found a video at ChemEd X (this is part of a ChemEd X subscription). It is entitled “Floating Squares – Hexane and Water” (see note below). I have placed both solutions together before, but I had not added the squares. The demonstration fulfilled my needs. I could have used the original video and muted it if I had not had hexane to demonstrate with.

Become a ChemEd X Contributor during BCCE 2014

Will you be attending BCCE 2014? There is still time to register! This is one of the best opportunities for high school chemistry teacher professional development. Grand Valley State University BCCE organizers have worked to make this year’s BCCE an affordable and valuable experience for high school level teachers. High school teachers may register at the reduced rate of $210 ($350 for regular attendees). If you are attending, I hope you will consider attending our ChemEd X Workshop. We will provide training to those interested in contributing their ideas with our community of educators. See the workshop abstract below. I hope to see you in August!

Cautious Chemist Corner #1

I was at a chemistry teacher workshop recently and we participated in a common Hess’s Law laboratory. Part of the procedure required us to measure about 2 grams of solid NaOH and add it to 100 mL of 0.5 M HCl. We also added 50 mL of 1 M NaOH solution to 50 mL of 0.5 M HCl solution. We then compared the energy change of both containers.

The Cautious Chemist Corner: Safety in the Classroom and Laboratory

Chemistry classroom accidents have been in the news too often recently. I hazard to suggest that there are smaller incidents that never make the news because there are luckily no serious injuries. We need to be vigilant in our safety concerns to protect our students and ourselves from any accidents and exposure to hazardous substances. We also need to be aware of theft concerns. Unfortunately, students may be looking for ingredients to experiment with explosives or to manufacture illicit drugs.