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…

Expensive, highly reflective barium sulfate plates are typically used to obtain solid-state UV-vis electronic spectra. Through normal laboratory use these plates become dirty, chip, and break, thus requiring replacement. An alternative to purchasing new plates is to make your own by combining a mechanical stabilizer, such as gum arabic, with…

We present an experiment designed to hone the decision-making skills of (undergraduate) chemistry students by using aqueous crossed aldol reactions. Here, we present two simple crossed aldol reactions based on inexpensive and readily available materials: The condensation of vanillin and cinnamaldehyde with acetone. The procedure uses the variation…

This laboratory experiment, designed for undergraduate nonmajors or advanced high school students, attempts to demystify the technique of spectrophotometry by utilizing a hands-on, real-world approach. Modification of the reaction for the formation of Fe[(bpy)[subscript 3]][subscript 2+] allows students to interact with vitamin C, a compound with…

The importance of understanding factors that contribute to surface wettability is highlighted in this new organic chemistry laboratory experiment, which aims to introduce the application of organic chemistry at the interface of polymer chemistry and material science. Polydimethylsiloxane (PDMS), a hydrophobic silicon-based rubber, is polymerized…

Glyphosate (N-(phosphonomethyl)glycine) is the most widely used herbicide on earth. A simple assay to quantify glyphosate concentrations in environmental samples was developed as part of an interdisciplinary effort linking introductory laboratory courses in chemistry, biology, and microbiology. In this 3 h laboratory experiment, students used…

Proficiency with instrumental analysis via GC-MS is an important skill for chemistry students. The application of analytical techniques and fundamental theoretical principles to real-world problems can be valuable learning exercises for undergraduates which can also improve their analytical thinking skills. Xylitol is generally considered safe for…

A laboratory experiment is described in which students determine the concentration and speciation of iron in beer samples using cloud point extraction and absorbance spectroscopy. The basis of determination is the complexation between iron and 2-(5-bromo-2- pyridylazo)-5-diethylaminophenol (5-Br-PADAP) as a colorimetric reagent in an aqueous…

Remote access technology in STEM education fills dual roles as an educational tool to deliver science education (Educational Technology) and as a means to teach about technology itself (Technology Education). A five-lesson sequence was introduced to 11 and 12-year-old students at an urban school. The lesson sequences were inquiry-based, hands-on,…

Here, students determine aspirin (acetylsalicylic acid) mass in pharmaceutical tablets using a colorimetric method. Aspirin, salicylate, and salicylic acid do not absorb visible light. Thus, in alkaline medium, acetylsalicylic acid was hydrolyzed to salicylate; then, it was reacted with an acidic Fe(III) solution, and a violet complex was formed.…

Micellar catalysis has become an important aspect of the chemical industry's effort to "go green". However, this chemistry has yet to be fully explored in educational settings such as second-year organic chemistry laboratories. Reported herein is a discovery-based nucleophilic aromatic substitution experiment that introduces chemistry…

In this paper, we report an experiment intended as a tool to introduce chemistry and materials science students to several chemical concepts through the determination of the best experimental conditions for the formation of calcium oxide (lime) from a source of high content of calcium carbonate (eggshells). Thermal gravimetric analysis (TGA),…

We report here a method that utilizes the vapor pressure of HCl(g) above a concentrated HCl(aq) solution as an extremely simple and safe method to produce small amounts of HCl vapor in an IR gas cell. This vapor pressure approach can also be used to produce DCl(g) by introducing a few drops of concentrated DCl(aq) into the gas cell.

Adsorption of methylene blue and malachite green was carried out using "Luffa cylindrica" sponges as adsorbing material. We provide a very illustrative exercise about the use of common natural materials requiring little preparation to solve environmental tasks in a routine laboratory situation such as using dyes. In addition, the…

An experiment involving a moisture-sensitive synthesis and spectroscopic characterization suitable for the advanced inorganic laboratory course is presented. The acid-base complex ammonia borane (AB) is synthesized from the heterogeneous reaction between sodium borohydride and finely ground ammonium sulfate in tetrahydrofuran solvent. AB is…