polarity

The Salting-Out Effect: A Colorful Demonstration That Leads to Student - Teacher Activities

Have you seen the "salting-out effect"? This interesting demonstration shows a separation of two layers in a solution of water and an organic solvent by adding an ionic salt. Although this concept has important applications in organic chemistry and biochemistry, it can also be visually stunning and engaging for audiences. Read on to learn how to incorporate this demonstration into your chemistry lessons.

Lewis Dot, VSEPR Shape, Polarity and Intermolecular Forces Activity Sheet

Determination of Lewis Dot structures and visualization of the shapes of molecules using VSEPR theory is an example of an abstract concept that students often find difficult to learn. I have found it useful to have a single worksheet/packet that my students can add to as we cover Lewis dot structures, resonance, VSEPR shapes, polarity, and intermolecular forces.

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.