Especially JCE: June 2017

June 2017 JCE issue

A voice piped up, “What if you tried it with a bigger marble?” I was thrilled to hear the third grader’s suggestion. It was a great extension to consider in the group experiment we were doing, but it was bigger than that. It was that the student had been automatically considering the “what if” possibilities of science, unprompted by me.

Blue Bottle Experiment: Learning Chemistry without Knowing the Chemicals (available to subscribers) in the June 2017 issue of the Journal of Chemical Education highlights the “what if” possibilities, on both the instructor and student sides of the classroom coin.

To begin, it shows the results of JCE authors considering “what ifs” related to the classic blue bottle experiment. If you haven’t seen it before, a solution in a plastic bottle undergoes multiple cycles of turning from colorless to blue and back again, as it is shaken and left to stand. They have developed resources for the use of what is often a demonstration so that students can use it in the laboratory. While the authors designed it to use with undergraduates (mostly nonchemistry majors) as a first lab experiment, it would also be an accessible experience for high school students. Each experiment also has suggestions for alternative procedures connected with certain parts. For example, they describe three different ways that you might provide a solution that has no air present in its container to help students realize that it plays a role in the reaction.

The “what ifs” for the students come in the series of suggested experiments. Students investigate the bluing process itself, finding that an atmospheric gas plays a role, but can then take it further by considering the way the solution is stirred, its temperature, and finally, other variations of their own choosing in a student-designed portion. The entire series was originally offered in a four-hour lab. I appreciate that the authors give a variety of experiments, but also understand that not all teachers will be able to use all of them. They provide tips for how you might pick and choose, and a suggested progression. They also include ideas for what students might consider during the open-ended investigation. Online supporting documents are included in Word format, so you can edit to your selected pieces.

In the abstract, don’t let the phrase “reaction mechanism” scare you off. The authors use a simplified treatment of the reaction, not sharing the specific compound names during the process. What they describe as a “mechanism” is more of a description of what happens, in an equation-style shorthand. For example, going from colorless (a leuco form of the compound, "L") to blue "B", through the addition of air "A" is shown as

L(aq) + A(g) à B(aq)

I have my own “what if…” I am curious as to how some of the suggested procedures would work with the chemicals used in the 2003 JCE Classroom Activity Out of the Blue. It used reactants available in stores, such as vitamin C powder and methylene blue and copper found in aquarium store products.

More from the June 2017 Issue

This post highlights just one piece of this month’s issue. Don’t miss the rest! Mary Saecker offers her summary of the content in JCE 94.06 June 2017 Issue Highlights.

Want to share your own “what if” moment related to an experiment or activity you’ve tried from the Journal? We want to hear! Start by submitting a contribution form, explaining you’d like to contribute to the Especially JCE column. Then, put your thoughts together in a blog post. Questions? Contact us using the ChemEd X contact form.