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.
In two connected ways, thermodynamics describes how both physical or chemical processes spontaneously trend towards equilibrium. This post is concerned with showing how free energy (ΔGrxn) changes as the reaction quotient (Q) changes as both trend towards the special condition, equilibrium, described by the constant K.
This post describes a simple way to generate blue, green, orange, and yellow copper complexes, and to use these complexes to introduce students to the effect of temperature on chemical equilibria. The protcol avoids the use of caustic agents, allowing the experiments to be conducted by students as a laboratory-based investigation.
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!
Solutions of copper (II) dissolved in acetone are easy to prepare, and can display orange, yellow, green, and blue color depending upon conditions. Such solutions allow for a variety of demonstrations and experiments that illustrate principles of chemical equilibrium.
My top 5 reasons for using Green Chemistry in my classroom along with a few examples of replacement labs that follow Green Chemistry principles.
This physical analogy relates to dynamic equilibrium and pits students against each other in a classroom-wide “snowball” fight. Not only is this activity great for building students’ conceptualization of dynamic equilibrium, it is also really fun!
The solution to "Chemical Mystery #16: A Red, White, and Blue Chemistry Trick for You!" is presented. How this experiment can be used as a springboard to carry out a simple quantitative analysis of salt solubility is also discussed.
A favorite demonstration is to boil water by lowering the pressure in a bell jar using a vacuum pump. Unfortunately, purchasing a bell jar, vacuum plate, and vacuum pump can run upwards of $1,000 which poses a hardship for many teachers. Here are two simple and inexpensive demonstrations of phase equilibrium and vapor pressure.
I was drawn to an article by Eilks, Gulacar, and Sandoval about Acid-Base Chemistry and Chemical Equilibrium in the April 2018 issue of JCE. The title of the article is "Exploring the Mysterious Substances, X and Y: Challenging Students' Thinking on Acid-Base Chemistry and Chemical Equilibrium." The premise of the article is to demonstrate how an instructor may use a group of compounds (zeolites) to "elaborate on the behavior of solid state acids and bases" while revisiting LeChatelier's principle.
