rate of reaction

Bubbly BBs and Vaccinated Mentos: Chemical Illustrations to Promote Public Health Measures

The authors revisit "flattening the curve" demonstrations published during 2020 to see how they could represent the impact of vaccinations on the COVID 19 battlefront. These demonstrations do not demonstrate the mechanisms of vaccines themselves, but are rather analogies to their potential effect on a population. In these analogies, gas production still represents illness, but this time people are represented by objects added to the solutions which either enable gas production (unvaccinated individuals) or do not enable gas production (vaccinated individuals). These simple experiments are best used as stand-alone demonstrations, and links to videos are included in this writeup.

Chemical Kinetics with a Smartphone

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.

Reflections from Kinetics - Solidifying Why I Teach Method of Initial Rates AND Integrated Rate Laws

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.

Fun and Quick Rates Lab (No pun intended...)

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.


Kinetics Review

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.

Where There's Fire There's...

In this Activity, students compare the combustion of different substances such as a glowing wooden toothpick and lit birthday candle in air, oxygen, exhaled breath, and carbon dioxide environments. The oxygen and carbon dioxide are generated from supermarket chemicals. This Activity can be used to explore the chemistry of oxygen and combustion.

The Effects of Temperature on Lightsticks

In this Activity, students observe and compare the behavior of three lightsticks that are exposed to three different temperature ranges (cold, room temperature, and hot). The Activity could be used early in the school year to give students practice in making detailed observations and devising reasonable explanations for those observations. It illustrates the use of qualitative vs.