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.
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.
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.
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.
