A Slinky is a loose helical coil spring and is a well-known educational toy. In this paper a model for a Slinky is presented. The Slinky is represented as a sequence of rigid half coils connected by torsional springs. A range of Slinky configurations in static equilibrium are calculated. Where possible the torsion spring model is compared with the…

The urea cycle disorder drug glycerol phenylbutyrate (Ravicti) is presently one of the most expensive medications in the United States, with annual costs estimated at $800,000 as of 2023. An expedient synthesis of this orphan drug was successfully adapted for the undergraduate organic chemistry laboratory. Activation of 4-phenylbutyric acid with…

Liquid metals are widely applied in various fields, including chemistry, catalysis, energy storage, chemical sensing, and stretchable electronics, due to their unique deformabilities. However, their behavior under a rod or ring electrode has never been analyzed. Furthermore, research on the deformation behavior of eutectic Ga--In (EGaIn), the most…

Anaerobic respiration reactions are of fundamental importance to global biogeochemical cycling of elements. Yet, the idea that cellular respiration can occur not only in the absence of oxygen but also involve the oxidation of inorganic substrates (e.g., AsO[subscript 3 superscript 3-], Fe[superscript 2+], H[subscript 2], H[subscript 2]S,…

The variation in the transference number of H[superscript +] (aq) is investigated for different HCl solution concentrations. The method for scribing graduations on electromigration tubes is modified to decrease the error in experimental measurements, and metallic copper is used as the anode to reduce the toxicity and environmental impact of the…

A mixture of salt water and isopropyl alcohol is immiscible, forming two separate liquids with the organic layer on top and aqueous layer on bottom. When universal indicator is added to such a mixture, all of the indicator compounds in the universal indicator preferentially dissolve in the alcohol--except for phenolphthalein at high pH. Mixtures…

As a rule, an experiment carried out at school or in undergraduate study courses is rather simple and not very informative. However, when the experiments are to be performed using modern methods, they are often abstract and difficult to understand. Here, we describe a quick and simple experiment, namely the enzymatic characterization of ptyalin…

Photochemical reactions are initiated by the absorption of light, triggering the chemical reactions and resulting in the formation of products. These reactions are generally performed using a freely available renewable source of energy-solar energy. Solar simulators mimic both the ultraviolet and visible regions of sunlight and hence can serve as…

The mathematical form of the magnetic field due to a current loop, and the fact that it is identical to the electric field due to an electric dipole in the far field, are fundamental to our understanding of electromagnetism. While undergraduate level electromagnetism textbooks usually derive the electric field from an electric dipole, few derive…

Concerns regarding students' difficulties with the concept of energy date back to the 1970s. They become particularly apparent for systems involving adenosine triphosphate (ATP), which plays a central role in maintaining the nonequilibrium state of biological systems and in driving energetically unfavorable processes. One of the most…

The addition of a small excess of triethyl orthoformate to an alcoholic mixture of NiCl[subscript 2]·6H[subscript 2]O and triphenylphosphine (PPh[subscript 3]) results in an increase in the typical isolated yield of [NiCl[subscript 2](PPh[subscript 3])[subscript 2]] from below 50% to over 85%. The impact of water when present in the reaction…

We describe the components and implementation of an activity for multivariable calculus featuring applications to the field of chemistry. This activity focuses on the isobaric thermal expansion coefficient found using partial differentiation of the volume of an ideal gas with respect to temperature as pressure is held constant. Broader goals of…

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…

Physiology concepts, such as acid-base balance, may be difficult for students to understand. Systems modeling, a cognitive tool, allows students to visualize their mental model of the problem space to enhance learning and retention. We performed a within-subjects three-period randomized control comparison of systems modeling versus written…

While elimination reactions are ubiquitous in organic chemistry textbooks, their implementation in undergraduate laboratories still suffers from a lack of reliable and easy setup procedures. This paper describes an easy-to-implement set of elimination experiments in the pentanol and bromopentane series using a modified Hickman distillation head.…