The separation of chamazulene from hydrophilic contaminants present in blue tansy oil provides a visually engaging example of two common techniques: extraction and thin-layer chromatography (TLC). This application uses liquid CO[subscript 2] as a lipophilic solvent to pull a brilliant blue hydrocarbon molecule, chamazulene, out of or through a…

This article reports on a new device, called a geyser guide, that allows for quantitative measurements of both bubble sizes and kinetics of foam production in the so-called Diet Coke and Mentos experiment. The device is easily constructed, is made using readily available materials, and allows the experiment to be carried out indoors with no mess.…

The so-called Diet Coke and Mentos experiment is initiated by dropping Mentos candies into a bottle of Diet Coke or other carbonated beverage. This causes the beverage to rapidly degas, causing foam to stream out of the bottle. Simple application of the gas laws leads to the straightforward prediction that ejection of greater foam volume is…

An experiment is described that uses easily obtained materials (glow sticks, chalk, and acetone or alcohol) to separate the dyes contained in glow sticks that actively emit chemiluminescent light. The experiment is very easy to carry out, making it amenable for students to perform in laboratory or outreach settings. The separation occurs fast…

When carbonated beverages (which are supersaturated solutions of aqueous carbon dioxide) are confined within a narrow-necked container, events which rapidly release the gas from solution produce a fountain out of the beverage. One well-known variant of this experiment is the addition of Mentos candies to a bottle of Diet Coke. Previous reports…

An activity is described wherein students observe dynamic floating and sinking behavior of plastic pieces in various liquids. The liquids and solids are all contained within a plastic bottle; the entire assembly is called a "density bottle". After completing a series of experiments that guides students to think about the relative…

A data set of 7,381 molecular iodine vapor rovibronic transitions between the X and B electronic states has been prepared for an advanced undergraduate spectroscopic analysis project. Students apply standard theoretical techniques to these data and determine the values of three X-state constants (image omitted) and four B-state constants (image…

Everyone enjoys seeing the cloudy white fog generated when solid carbon dioxide (dry ice) is placed in water. Have you ever wondered what physical and chemical processes occur to produce this fog? When asked this question, many chemical educators suggest that the fog is produced when atmospheric water vapor condenses on cold carbon dioxide gas…

Coulometric titrations involve the quantification of analyte by measurements of current and time. In most coulometric titrations, the anode and cathode are placed in isolated cells that are connected by a salt bridge. By contrast, the experiments described here involve coulometric titrations (of acidic protons in solution) using a silver anode and…