In today's global economy, the origin of the food we eat is becoming more and more difficult to identify. Verifying the authenticity of products to protect supply chains is a complicated problem that requires a multidisciplinary approach. Chemical authentication of foodstuffs often includes a mass spectrometer detector; however, they are costly…

Potash, an essential raw material of the 18th century, used to be produced from the ashes of plants. Known since antiquity, it was in 1807 that Humphry Davy put an end to the decades-long controversy about its nature as a compound. The technology behind potash production was implemented in Brazil by the Portuguese naturalist Frei Velloso. The…

A procedure to purify anthocyanin, a natural pigment, following a green approach by using macroporous resin and its encapsulation for the maintenance of its stability is described. This laboratory experiment, which describes the benefits of using resin for the purification, is a learning tool for students working in the field on nutraceuticals.…

An experimental design by combining hydrogel and ethylenediaminetetraacetic acid disodium salt (EDTA) for visually displaying chemical complexation reactions is developed. The Na[superscript +] ions on the [alpha]-l-guluronic acid (G) unit of the sodium alginate molecule undergo an ion exchange with a divalent cation, so that the G units are…

This article describes an enrichment and extension of a published applied chemistry experiment involving the use of distilled fragrant compounds of natural plants to prepare facial toner. The original protocol failed to consider quality evaluation of the self-prepared facial toner. Herein, an additional experimental section is included for…

A single-slit diffraction experiment in an introductory physics laboratory is generally comprised of a rectangular slit and a laser source. The laser beam is sent to the slit producing the well-known diffraction pattern on the screen. This paper proposes a simple modification of the single-slit diffraction experiment to increase student attention…

There is a large variety of goals instructors have for laboratory courses, with different courses focusing on different subsets of goals. An often implicit, but crucial, goal is to develop students' attitudes, views, and expectations about experimental physics to align with practicing experimental physicists. The assessment of laboratory courses…

The Crookes radiometer (also known as a light mill) is a fascinating sunlight-powered device, in which a set of vanes is placed inside a glass bulb within which a partial vacuum has been pulled. The vanes then rotate when sunlight shines on the bulb. The reason for the turning of the vanes was subject to intense debate and many students still have…

The article describes a methodology for studying Fresnel diffraction with the active involvement of students in discussing the results of a demonstration experiment. To create a clearly visible model of Fresnel zones, a centimeter radio wave range was chosen, in which the first zone is about 10 cm in size. This makes visible the created…

E-learning is not a new concept to the American University of Nigeria (AUN); however, it has always been applied to the lectures but not in the laboratories for the chemistry courses before and during the first phase of the COVID-19 lockdown. The sudden disruption of learning caused by the forced lockdown issued by the government authority in an…

This work describes the design and testing of a low-cost light-emitting diode (LED)-based nephelometer for turbidity analysis. It also describes the use of this nephelometer for context-based learning (CBL) experiments designed for teaching laboratories. The LED nephelometer is simple, low-cost, and robust, providing similar results as a…

Successful demonstration of lipid assembly chemistry to a general audience can be challenging on both physical (nanoscopic dimensions of lipid assemblies) and intellectual (complex, interconnected concepts) accounts. Quite often, an instructor has to leave key concepts out of what is being offered due to time constraints, which unfortunately…

NMR spectroscopy is a powerful spectroscopic tool that not only allows the determination of structures after synthesis, as usually explained to students of Organic Chemistry, but also is useful in many other fields such as medicine imaging, real-time industrial processes, material sciences, or metabolomics. In this experiment, students performed a…

We propose a laboratory experiment on the quantitative study of the normal dispersion of light. A triangular isosceles prism made of flint glass TF3 is used as the object of study, and we describe a simple and affordable device for observing and photographing the dispersion spectrum on a smartphone. A possibility of the quantitative investigation…

Virtual chemistry laboratory modules were investigated as a potential learning resource that complements traditional in-person experiments. In collaboration with a high school instructor, we designed two interactive modules, "Rates of Reaction" and "Models of Organic Molecules," which became part of a previously reported online…