A simple experiment is described to compare the descent time between two vertically separated points when an object slides down tracks of varying shape. A surprising result is that the descent time is shortest when it follows a circular track rather than a cycloidal track. Cycloidal tracks are usually predicted to result in the shortest descent…

The direct involvement of students in conducting experiments in order to learn science has been a common part of U.S. educational practice since the late 19th century, the result of the rapid spread of what was known as the "laboratory method" of teaching. Those promoting the laboratory method recognized it as a new educational approach,…

Scientific reasoning competencies enable students to engage in scientific inquiry through a wide range of methods, for example by asking questions, formulating hypotheses, and planning, carrying out, and evaluating experiments. Laboratories are particularly suitable to foster these competencies in higher education. In order to give lab educators…

Spectroscopic characterization of molecules is typically reinforced in the organic chemistry teaching laboratory via the analysis of reaction products by NMR and IR, and initial coverage of these topics can include experiments involving the identification of unknown compounds. To combine the unknown identification component with common laboratory…

A discovery-based experiment for the synthesis of arylpropiolic acids via carboxylation of arylacetylenic Grignard reagents was developed. This experiment shows the "dual utility" of Grignard reagents. In the synthesis of arylpropiolic acids reported here, we have demonstrated the use of a Grignard reagent as a base in a "Grignard…

Electrochemical impedance spectroscopy (EIS) is a rapid and powerful method for evaluating the pore structure of membranes. However, the application is limited due to the lack of appropriate training of engineers in electrochemistry and materials engineering. The introduction of laboratory practices can effectively improve the understanding of…

In recent years, the food industry has been undergoing major changes driven by new social and environmental demands. Nowadays, biodegradable packaging is perceived as the most feasible alternative for food packaging. Great efforts are being devoted to the development of new materials from agro-industrial wastes and byproducts that are opening new…

A laboratory experiment for the determination of the cross-linking density of silicone elastomers is described on the basis of swelling experiments and mechanical tests. In the experiment, the macroscopic swelling and mechanical behaviors of the elastomers were discussed as a function of the cross-linking density, which can be easily controlled by…

Flavor plays a crucial role and is the most important aspect of foods and beverages. [Beta]-Ionone is a common flavor compound with a characteristic violet-like odor. An undergraduate flavor compounds chemistry laboratory that provides preparation and characterization of the flavor compound inclusion complex between…

In this laboratory experiment, students apply a mass-based approach to determine the Henry's law constant for CO[subscript 2] using a small bottle of a diet carbonated beverage. The calculations are challenging; therefore, team-based learning is encouraged. Our students reported values of 0.033 ± 0.003 mol/(L[middle dot]atm) at room temperature…

This laboratory experiment introduces students to an important reaction in biomass valorization and allows them to gain a practical understanding of green chemistry. Acid-catalyzed dehydration reactions of fructose to 5-hydroxymethylfurfural and thus humins were performed both with and without aqueous solvent, along with two different catalysts…

This paper describes a new lab experiment where students explore the magnetic force on a permanent magnet placed inside a short solenoid. This lab is the fourth experiment performed in the second semester of the calculus-based introductory physics course at Washington University in St. Louis. The experiment is performed using a speaker (which…

An experiment was developed for a first year food chemistry laboratory course that demonstrates the influence of several aspects of polysacharide structure on the rate of amylase catalyzed hydrolysis. The experiment would be particularly well-suited to a first year chemistry course that was targeted at nonchemistry majors, such as health related…

Inorganic Chemistry teaches students the concept that modifications to ligand structures, especially the donor properties, can have a drastic impact on the reactivity and stability of the metal complexes. Experiments described here reinforce this concept through the investigation of two tetradentate ligands derived from…

The acid-catalyzed dehydration of regioisomeric methylcyclohexanols is a classic organic chemistry experiment featured in a variety of laboratory textbooks and literature. The mechanistic details of this reaction have received an inconsistent and occasionally inaccurate treatment, wherein the reaction has been described as a mix of E1, E2-like,…