Owing to factors such as poor water solubility of luminol and the instability and easy decomposition of hydrogen peroxide (H[subscript 2]O[subscript 2]), the accuracy and sensitivity of the detection of H[subscript 2]O[subscript 2] through the luminol electrochemiluminescence (ECL) system are limited. Herein, we propose a water-soluble…

Ion transport, involving the diffusion and migration of ions within the electrolyte, stands as a fundamental concept in electrochemistry and serves as the driving force for electrochemical reactions. Electric double layers are critical in the fields of electrochemical energy storage and chemical conversion, constituting a central focus of…

The early 20th century marked a number of transformational experimental and theoretical discoveries in physics. Among them is one that is often neglected in the introductory physics curriculum, which revolutionized our understanding of the molecular world. Evidence for the thermal motions of atoms was first observed by Perrin in 1909, which had…

Although diffusion is the subject of beginning chemistry classes, there are a variety of experiments, such as the spread of perfume in the classroom, that are often "incorrectly" explained by diffusion alone. To eliminate this common misconception, a recently published method is modified to determine the diffusion constant of hydrogen…

After a time away from the classrooms and laboratories due to the global pandemic, the return to teaching activities during the semester represented a challenge to both teachers and students. Our particular situation in a Microbial Physiology course was the necessity of imparting in shorter time, laboratory practices that usually take longer. This…

The activity proposed in this study aims to investigate the equilibrium between the liquid and vapor phases in a mixture of water and acetic acid, both of which are volatile substances. High school students can easily determine the composition of the liquid phase and its corresponding vapor phase at equilibrium using a simple and conceptually…

Gravity bends light. One can argue this by reasoning that a beam of light should travel in a curved path when viewed from within an accelerating frame of reference, and then invoking Einstein's principle of equivalence, which asserts that the effects observed in an accelerating frame of reference are indistinguishable from the effects observed in…

The family resemblance approach to nature of science is receiving increasing attention by science educators since its inception about a decade ago. Many scholars of science education have contributed and continue to contribute to it not only theoretically but also by applying it empirically to a wide range of areas such as curriculum and textbook…

In this two-session experiment for an organic chemistry lab, students prepare a macrocyclic host compound--namely, a pillar[5]arene--by means of a templated 1,4-dimethoxybenzene/formaldehyde cyclo-oligomerization (session 1), and then, they explore its molecular recognition properties toward the 1,8-diaminooctane guest with the aid of [superscript…

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…

Nearly everyone, including physics students, finds rainbows to be fascinating and much has been written about them. For example, in a 2020 paper, Kenneth Ford sets forth the basic theory of rainbows created by water droplets at the level of geometric optics and uses a graphical approach to address the question of the relative intensities of the…

Atwood invented a machine in the 1780s that enabled him to observe the motion of a falling body as slowly as desired. This machine was equipped with the necessary means to measure the distance covered by the body and the time taken. With this data, it was possible, in addition to studying the falling motion, to calculate the local gravitational…

In this paper, we utilize the readily known theory of the ideal transformer to furnish a self-contained qualitative explanation on the AC-powered Thomson jumping ring (TJR) experiment.

The "Golden Penny" demonstration is a popular experiment that involves treating copper coins with chemical reagents to form brass, an alloy of copper and zinc that has a golden color. Reported here is a very simple modification for forming golden color on copper coins that does not require the use of chemical reagents. Instead, golden…

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…