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.
Chemical kinetics is one of the five challenge areas in AP Chemistry. My students and I have been working our way through one of the teaching and learning activities called Concentration vs. Time. The graphical analysis, guided-inquiry questions, and application to past and future content are seriously challenging, and my students report higher levels of understanding than in past semesters.
I taught my students how to use the method of initial rates. I taught my students rate laws. However, they strugged to differentiate when to use what method. Upon further probing, they struggled to articulate why one might use one method over the other. They could parrot back some ideas ("The rate law tells you about the particles involved in the rate determining step of the reaction."), but I wasn't convinced of mastery and connections.
I am facing what many teachers are facing. It is AP week, I am trying to continue "as usual" with doing labs and learning but this time of year is anything but "as usual". There is a rates lab we do this time of year which is a good lab, rather involved with a significant amount of set up and work. I got an idea for a slightly different rates lab from Bob Worley. I found a similar large scale version from Flinn Scientific. Thanks to Bob, I decided to do a microscale version.
In one of my last blog posts I wrote of how I sometimes enjoy ending a unit with a series of demonstrations and using them to elicit a dialog between the students and myself to check for understanding. It is always a fascinating experience to hear the misconceptions that many students have the day before the test.
