HS-PS1-2 Chemical Reactions

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.

Color Changing Coke and Mentos

What's a better way to start the new school year than with some new experiments? Learn how to use a variety of color changing experiments to teach students about the Diet Coke and Mentos experiment, acids, bases, chemical and physical changes, and climate change.

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.

Making a (big) eruption with chemistry!

As teachers, we can leverage fruitful discussions about chemical control with students to elicit more about students' initial ideas and ways of reasoning. From asking students to clarify their own thinking, we can identify students’ own productive ideas that we can capitalize on to advance their thinking.

A Multi-Colored Equilibrium Experiment

Solutions of copper (II) dissolved in acetone are easy to prepare, and can display orange, yellow, green, and blue color depending upon conditions. Such solutions allow for a variety of demonstrations and experiments that illustrate principles of chemical equilibrium.