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.
This experiment in chemical kinetics can be conducted using materials as simple as a smartphone, hydrogen peroxide, sodium carbonate solution, and blue food dye! The experiment is useful when discussing the order of rate laws with respect to reactants.
Given a guiding question, students determined what they wanted to test, did the experiment and got their CER boards ready for review. Instead of a regular argumentation session, we had a glow and grow session, where students had to provide positive and negative feedback for each board.
You are likely aware that diamonds are converted - albeit slowly - to graphite under normal conditions. Thus, diamonds don't last forever, in contrast to the popular advertising slogan. However, did you know that you can use chemistry to prove that diamonds are not forever? It's simpler than you think...
In this blog post, I would like to share a relatively simple demonstration you may use to introduce the concept of antioxidant along with its potential in everyday life.
In the embedded video, I will walk you through a kinetics experiment we use in our Chemistry 2 (and Honors Chemistry 2) courses. The lab is called Disappearing X.
A classroom activity to demonstrate the principles of chemical kinetics and equilibria and the utility of the mole concept is described here. The activity involved no hazardous materials or complex equipment and can be enjoyed and appreciated by general studies students as well as chemistry majors.
As part of a two-week Chemistry Modeling Workshop™ in Houston, TX, I had the opportunity to read the Journal of Chemical Education article “When Atoms Want” by Vicente Talanquer of the University of Arizona. I researched Dr. Talanquer and discovered he created a collection of simulations called Chemical Thinking Interactives (CTI). These digital tools illustrate many chemistry topics with a focus on the particulate nature of matter.
I recently stumbled upon this article and it is a super handy resource for kinetics labs (and a nice review of Analytical courses from my college days).
Whether you are introducing collision theory or something more demanding like reaction order, the reaction between sodium thiosulfate—Na2S2O3 and hydrochloric acid can provide a consistent, accurate, and engaging opportunity for investigating these topics.