polarity

Teaching VSEPR theory presents some unique challenges for students - particularly picturing molecules in 3-D space. I have found manipulatives to be a powerful tool to help students visualize 3-D molecules. Here are some of my favorite manipulatives for teaching VSEPR and cheap at-home modifications for virtual learners.

Two years ago, I saw a post here on ChemEd X about popping a balloon with an orange peel--and from this seed grew one of my favorite weeks of the school year.

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.

Wow! Talk about an interesting idea! A very neat experiment, called “Hydroglyphics”, has been published by Philseok Kim, Jack Alvarenga, Joanna Aizenberg and Raymond Sleeper in the Journal of Chemical Education.