Carbonated beverages have long provided chemical educators and other teachers of science with an easy-to-obtain system that connects to several physicochemical concepts. For example, many educators have devised experiments to determine the pressure of CO[subscript 2] contained in commercial carbonated beverages, but the role of temperature in such…

In this paper we consider the well-known experiment with the 'heavy' newspaper that breaks a stick that it is laid on. Using several appropriate control experiments we show that the currently invoked explanation using atmospheric pressure cannot be correct. We perform a theoretical analysis and propose a new explanation based on the rotational…

This paper introduces a safe, interesting, convenient, and low-cost experiment. The products of galvanic cells and electrolytic cells are compressed into specimens that are placed on a slide to stretch the metal dendrites in one plane and ensure they are not easily destroyed by external factors. The details and growth process of the metal…

A previous journal article established that a hanging Slinky's restoring force is due only to the coils between the support and the Slinky's center of mass (hereafter COM). Correspondingly, it is expected the Slinky's elastic potential energy (hereafter EPE) is associated with only those coils; however, there is no confirming experimental…

According to Einstein's general theory of relativity, a clock runs more slowly if it is close to a large gravitating object. This principle was highlighted in the movie "Interstellar," in which the main character spends several hours on a planet orbiting a massive black hole, and returns to find that his young daughter has become an…

Understanding experimental design (e.g. control of variable strategy or CVS) is foundational for scientific reasoning. Previous research has demonstrated that demonstrations with cognitive conflict (e.g. asking students to evaluate and explain different experimental designs) are effective in promoting children's scientific reasoning, however, the…

Most didactic lab experiments deal with the influence of temperature, concentration, pressure, surface area, and catalysts on chemical kinetics; however, few of them explore the influence of light radiation and the presence of inhibitor agents on reaction rates. In order to investigate the effects of the radiation source and the presence of…

A versatile experiment is described for the high school and college laboratory setting based on the synthesis of biobased polymers prepared from inexpensive, renewable, and nonhazardous chemicals. Combinations of readily available citric acid, glycerol, and tapioca root starch are used to prepare three polymeric materials with different observable…

Regioselectivity in hetero Diels-Alder reactions can be observed in a simple reaction between a nonsymmetrical heterodiene and an unsymmetrical heterodienophile. A 9 h and easy to implement laboratory experiment is described, in which students can observe the regioselectivity of inverse "electron-demand" hetero Diels-Alder reactions of…

A creative apparatus for use in a hands-on laboratory experiment that allows the visualization of the vapor pressure as a function of temperature is described in this paper. Inspired by homemade barometers and using simple materials that are easily accessible for teaching laboratories, a lowcost system for the establishment of the vapor-pressure…

Typical laboratory exercises for undergraduate organic chemistry students involve bulk phase reactions with work up of product. In this study, students performed accelerated versions of the Katritzky reaction of para-substituted anilines with pyrylium salts in three ways: (i) by dropcasting reagents onto a paper surface and allowing solvent to…

A series of computational laboratory experiments aimed at teaching students principles of rational drug design are described and evaluated. These experiments range from an introduction to viewing protein-ligand complexes to optimizing geometries of potential drugs with quantum chemistry and automated docking. Student feedback indicates that such a…

It is a well known fact that the Earth carries a net negative charge that produces a downward electrostatic field. The present experiment shows how this field can be measured with a Field Mill which has been constructed from components readily available in the Laboratory. In fine weather conditions a value of 120 (±10) V m[superscript -1] was…

Much of analytical chemistry involves the analysis of complex mixtures, where careful attention to sample preparation and method selectivity is required to avoid interferents and obtain accurate data. As this type of analysis is very different from simple colorimetric analysis that most students are exposed to in general chemistry, this laboratory…

In an article in this journal, it was shown that air resistance could never be a significant source of error in typical free-fall experiments in introductory physics laboratories. Since projectile motion is the two-dimensional version of the free-fall experiment and usually follows the former experiment in such laboratories, it seemed natural to…