This experiment combines analytical techniques of solid-phase extraction (SPE) and gas chromatography quadrupole time-of-flight mass spectrometry (GC-QTOF-MS) to determine organochlorine pesticides (OCPs) in river water as a means to develop and improve student understanding of the use of GC-QTOF-MS for qualitative and quantitative analysis. In…

Organic electrosynthesis is an increasingly popular tool for driving and probing redox reactions. Recent advances in this field often employ an electrocatalyst to enhance the selectivity and efficiency of electrochemical reactions. A laboratory experiment was developed to introduce students to relevant mechanistic techniques in electrochemistry…

In an idealized General Chemistry Laboratory curriculum, students would hone their experimental design ability with practice encouraged by laboratory exercises designed to be open-ended. However, traditional General Chemistry Laboratory courses often lack opportunities for students to design their own experiments, instead opting to provide…

Highly efficient microwave-assisted organic synthesis is now commonplace in both industry and academia. Recently, a conductively heated sealed-vessel reactor was introduced that acts very similarly to a microwave reactor and is more affordable. Application of such reactors in teaching laboratories is advantageous because of the restricted window…

Recognized as one of the most beautiful experiments of all time, the oil drop experiment performed by Robert Millikan and his graduate students (primarily Harvey Fletcher) is a standard in the repertoire of experiments performed by undergraduate physics students. However, "as a teaching lab it does not enjoy a good reputation for three…

The dynamic study of pendulum systems is considered an indispensable subject for physics and mechanics students in colleges and high schools. In this paper, a detailed methodology is given concerning the use of smartphones in pedagogical practical work for studying the dynamics of pendulum systems. Whereas, three aspects have been discussed…

At constant current (I) the forward bias potential (V) of a "pn" junction diode may be considered to vary linearly with temperature (t) within a temperature range. Based on this property we have constructed diode thermometer using germanium (Ge) and silicon (Si) diodes. The experimental "V-t" data at constant forward current…

The formation of chemical patterns is in general difficult to control due to the random diffusive motions of the reacting chemical species in solution. In this paper, we present a new method using audible sound to control the formation of chemical patterns obtained in blue bottle experiments. The waves generated on the surface of the solution by…

The purpose of this publication is to present a novel approach to the demonstration of the Dzhanibekov effect. The main idea of our version is to use a lightweight spinning top of a spherical external form but distinct principal moments of inertia floating in the upward flow of air. As a result, the Dzhanibekov effect can be easily demonstrated…

We investigated a very long chain falling from the pile on the edge of a table to the floor both experimentally and theoretically. In this very simple and novel configuration we showed that the velocity of the chain quickly converges to its asymptotic value, and that the steady-state velocity is proportional to the square root of the height of the…

The measurement of the charge-to-mass ratio, e/m, of the electron is a fundamental part of any study of electricity and magnetism. It is possible to use an apparatus designed to measure e/m for other things, including investigations of electron flow through a near vacuum, measuring a work function, and even exploring some quantum mechanics…

Our first experience of dimension typically comes in the intuitive Euclidean sense: a line is one dimensional, a plane is two dimensional, and a volume is three dimensional. However, following the work of Mandelbrot, systems with a fractional dimension, "fractals," now play an important role in science. The novelty of encountering…

In this paper, a simple method is described for visually demonstrating that the wavelength of light reduces when entering a medium of higher refractive index. When a violet laser (405 nm) is reflected off the surface of a Blu-ray disc (track spacing 320 nm) diffraction cannot occur since the wavelength is greater than the track spacing. However,…

Applying the idea of green chemistry, we extended an esterification teaching experiment with isoamyl alcohol and acetic acid and reused isoamyl acetate in the transesterification reaction with KOH as the catalyst. As a result, isoamyl alcohol was produced and could be reused for the teaching experiment. The simplified experimental method achieved…

A set of inexpensive and pedagogically rich experiments focusing on S[subscript N]1, E1, and E2 reactions have been updated to include modern computational and spectroscopic analyses. The S[subscript N]1 experiment involves treatment of "tert"-amyl alcohol with hydrochloric acid to generate the corresponding alkyl chloride, which is used…