activity

A guided group inquiry lesson on coordination compounds and complex ions

Michael Morgan shares a lesson that he has used for many years that not only requires students to explain a topic that they have not been directly taught but also to develop explanations based on previous knowledge. He has used this lesson as a multiday “in-class” assignment and also as an “at-home” independent study. It works well in both scenarios with only minor revision. The lesson is based on Alfred Werner’s work on deducing the structures of coordination compounds.

Aqueous red cabbage extracts: More than just a pH indicator

The use of anthocyanins in red cabbage extracts as pH indicators has long been a popular classroom activity. Flowers, fruits and vegetables contain a diverse range of anthocyanins. This investigation explores further applications of plant-derived dyes including reversible reactions based on oxidation/reduction chemistry and other reactions to illustrate colour changes that are not solely dependent on pH change. By using household materials and plant dyes, this investigation may potentially be completed at home if necessary.

Chemical Illustrations of Flattening the Curve

With the current global COVID-19 pandemic, there has been much discussion of “flattening the curve” by social distancing. These ideas can be demonstrated chemically, for example, by the iron-catalyzed decomposition of hydrogen peroxide to produce an oxygen gas foam. Decreased hydrogen peroxide concentrations, representing decreased human population concentrations from social distancing, produce oxygen gas foam, representing cases of illness, at a slower rate. A similar demonstration can be achieved using the popular Diet Coke and Mentos experiment. These simple experiments are best used as stand-alone demonstrations.

Measuring Surface Tension to Investigate Intermolecular Forces

Like most concepts in chemistry, intermolecular forces takes a bit of imagination and critical thinking to fully comprehend and apply when explaining a variety of situations. Though demonstrating the presence of these forces in a simple and explicit manner can easily be done, I wanted to change how I introduced IMFs a bit this year by focusing on a more data-to-concepts approach.

Detection of Nickel Cations in Coins

It is not known why people develop allergies to nickel and there is no cure. The best course of action to prevent an allergic reaction is to avoid contact with products containing nickel. This article will explain how to make an easy and cheap nickel detection device that will limit or eliminate the risks of exposure to sources of nickel using some interesting classic chemistry. 

Immobilization of Lactase Enzyme on Alginate Beads - A Quick Test

I came across an interesting Journal of Chemical Education article that explains how it is possible to crosslink sodium alginate, leading to the formation of calcium alginate beads. Calcium alginate beads are hydrogels and one of their uses is to immobilize enzymes in their structure. I thought it would be cool to immobilize some lactase enzyme onto calcium alginate beads and investigate its ability to hydrolyze lactose. 

Moving Beyond Le Châtelier

Is it time for us as chemistry teachers to move beyond the Le Châtelier Principle as justification for why disturbances to equilibrium systems cause particular “shifts”? The author shares his new approach to teach equilibrium and provide his students with a more rigorous understanding of the concept.