The purpose of this variation on the “dragon’s breath” demonstration is to illustrate that face masks can diminish the movement of particles in the air, an important idea in public health.
HS-PS1-5 Rates of Reactions
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.
My top 5 reasons for using Green Chemistry in my classroom along with a few examples of replacement labs that follow Green Chemistry principles.
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.
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.
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.
You can perform an orange to black chemistry demonstration using materials commonly found in stores. The reaction appears to be similar to the Old Nassau reaction, but uses greener reagents. This is a great demonstration to do around Halloween time.