The Young's two-slits experiment is arguably one of the most famous and beautiful experiments in physics. In introductory physics labs the experiment is almost exclusively carried out using a laser, and it is introduced this way in some introductory physics textbooks. In the case of laser illumination, light passes directly through the slits and…

An experiment is described where a billiard ball and a golf ball were projected with backspin on a horizontal surface to measure the transition from sliding to rolling. During both phases, the torque on the ball is affected by an offset in the line of action of the normal reaction force.

The curriculum for undergraduate Agricultural Engineering does not usually include much laboratory practice. In order to address this, here we propose the design of a practical class on legume-rhizobia symbiosis, using an interdisciplinary approach that takes elements from botany, agriculture, and microbiology. The students perform an assay to…

Short chain fatty acids (SCFAs) are produced in the gut as a result of microbial action on ingested dietary fiber and have been associated with several health benefits. Herein an undergraduate student experiment that uses gas chromatography equipped with either a flame ionization detector or mass spectrometer for the analysis and quantitation of…

Lakes are artists' pigments made from colorants bound to an inert substrate, usually hydrated aluminum oxide. Before the late 19th century, lakes were made from natural pigments extracted from plants and insects, extracted either directly from the dyestuff or indirectly from waste materials generated in the manufacture of dyed textiles. The first…

A comprehensive teaching experiment plan tailored forthird-yearundergraduates has been developed. Initially, instructors synthesize(E)-2-(4-((4-(2-hydroxyethoxy)-3-methylphenyl)­diazenyl)­phenoxy)-ethan-1-ol­(M-Azo-2)monomer as part of the preclass preparation. Subsequently, studentsperform an acylation reaction experiment to prepare an…

Most students enter college without any exposure to polymer science, which leads to the poor understanding and slow implementation of plastic recycling programs in the United States. To address the knowledge gap in chemical recycling, we introduce a 2-part laboratory experiment that was conducted in multiple high schools and public outreach events…

Although the present university-level chemistry experimental curriculum has been extensive and well-designed, it lacks a connection with the scientific research field, especially the frontier field. It is crucial to incorporate recent discoveries through new experiment designs to bridge this gap and boost the value of the undergraduate…

The substitution of carbonyl compounds with liquid bromine as a brominating agent is the most commonly employed synthesis method for a-bromoacetophenone and its derivatives. However, liquid bromine possesses certain drawbacks, such as volatilization, high toxicity, strong corrosion, and poor reaction selectivity, which limit its application and…

Here, a relatively simple laboratory experiment of a physical pendulum, suitable for students of science and engineering in the first courses of university physics, is presented to illustrate its dynamic behavior and to determine its inertia moment. To this end, a long wooden rod of length L = 99.8 cm and cross-section radius R = 1.73 cm was used…

An activity is described that uses simple materials and an easy-to-perform protocol to estimate the Curie temperature of nickel, which is the temperature at which nickel loses its ferromagnetism. To do so, an object made of nickel metal is heated with a lighter until it loses its ferromagnetism. The metal is allowed to drop into a beaker that…

We have developed a guided-inquiry laboratory exercise in which students perform viscosity measurements to infer the structure of poly(vinyl alcohol) (PVA) in aqueous solution. The activity combines both experiments and modeling. In the experimental portion of the exercise, students measure the viscosity of several solutions of PVA with differing…

This experiment demonstrates that copper(II) chloride dihydrate (CuCl[subscript 2]·2H[subscript 2]O) in different solvents (acetone, isopropyl alcohol, or water) displays divergent colors and visible-near IR spectra. Both the reactions of these solutions with 2 equiv of sodium hydroxide (NaOH) and the direct solid-state reaction of CuCl[subscript…

Electrochemistry is taught in most undergraduate chemistry programs. Although this topic is important for students due to its broad interest in industry (energy, diagnostics, car industry, etc.), they often find it difficult, because it is based on a combination of various physical concepts such as electric fields, interfacial processes or charge…

The construction and characterization of a glucose biosensor has been implemented in an instrumental chemical analysis course to provide students experience with chemical sensing, electroanalytical methods, and flow injection analysis (FIA). The glucose biosensor was assembled on a glassy carbon electrode by depositing a layer of Prussian blue…