A Soviet era stamp featuring a quadruple bond.
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.
In this lab, students connect the workings of an electrochemical cell in the lab with the symbolic equations used in electrochemistry and manipulate a model representing the particulate level of what is happening during the electrochemical process. Although this lab was previously highlighted on ChemEd X, there are now virtual options offered!
Assembling a large graduated cylinder with colored sugar solutions of various densities is described. By filling the cylinder in the reverse order from bottom up, very little mixing occurs resulting in an attractive classroom demonstration to illustrate density. Students also have to opportunity to practice density and dilution calculations.
Ben Meacham decided to alter his approach to teaching about enthalpy and focus on getting students to first develop the mathematical model for enthalpy of solution so they could eventually apply it to make predictions for different solutes being dissolved. In this blog post he shares the process he used with his class.
The demonstration where CO2 is generated and used to snuff out a candle in an aquarium or other container is well known. This article describes a dramatic variation on these demonstrations that allows for discussion of such topics as the ideal gas law, densities of different gases, gas density changes with temperature, miscibility, and viscosity. The device described is easily and inexpensively produced and stored. The demonstration is large scale and works well for classrooms and community outreach events.
Infrared technology (FLIR Cameras) can be used to investigate intermolecular forces.
The blossoms of eastern skunk cabbage produce heat for a couple of weeks in early spring. This heat, which can be detected using an infrared camera, results from oxidation of carbohydrates. The mechanisms behind this process can be used to introduce energy transduction during classroom discussions of thermochemistry.
Observing the floating and sinking behavior of diet and sugared sodas is a classic chemistry demonstration. Learn how to perform this experiment as a quantitative lab that can be accomplished as an at-home activity!
Service animals will continue to become more common in chemical laboratories. It is important that chemistry faculty and departments are prepared to safely accomodate students with service dogs in laboratory courses.