Ryan Johnson and I took a trip to the top of Pikes Peak to study the Coke and Mentos experiment. And we had a few surprises along the way...
When iron spheres at room temperature are added to liquid nitrogen, the nitrogen boils as heat is transferred in from the iron. The amount of liquid nitrogen boiled depends on the amount of heat transferred, which depends on the mass of the iron added. However, the rate at which liquid nitrogen boils depends on the surface area of the iron in contact with the liquid nitrogen. These phenomena can be studied with experiments which measure the mass lost by the boiling liquid nitrogen.
Dean Campbell tries to use at least one demo for every class to illustrate concepts described in his chemistry courses. In this post, he includes short descriptions of the demonstrations and props he has used while teaching his collegiate General Chemistry II courses.
Why does the "Whoosh Bottle" experiment behave differently at different temperatures?
The classic classroom or lab activity using coin flips to illustrate the first order kinetics of radioactive decay is connected to the tragedy of radiation exposure of workers at facilities using radium-containing luminescent paint. Some of the chemistry related to the contamination of these “radium girls” is explored, with connections being made to the Principles of Green Chemistry and the United Nations Sustainable Development Goals.
Helping students develop abstract understanding is a universal goal. This article describes an activity that involves students developing and then solving novel quantitative chemistry problems following a MadLibsTM style framework.
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.
What is the pressure inside a bottle of soda pop? Read this short article to find the surprising answer to this question, and also to learn how to do an experiment to answer this question for yourself!
In this lab students are given a film canister, a quantity of Alka Seltzer of their own choosing and any materials available in the room to investigate factors that affect the rate of reaction. They work with their groups to create CER boards and then the class engages in a Glow and Grow session. Tips for using this activity in a virtual setting are offered as well.
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.
