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…

Most biochemical transformations involve more than one substrate. Bisubstrate enzymes catalyze multiple chemical reactions in living systems and include members of the transferase, oxidoreductase, and ligase enzyme classes. Working knowledge of bisubstrate enzyme kinetic models is thus of clear importance to the practicing biochemist. However,…

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…

A new experiment based on phase inversion of Pickering emulsions was carried out in a physical chemistry course. The emulsions were stabilized by surfactant-modified SiO[subscript 2] particles. As the concentration of surfactant increased, the emulsions changed from oil-in-water type (O/W) to water-in-oil type (W/O) type, and then reverted to be…

Purpose: The purpose of this study was to identify whether post-resistance exercise (REx) blood flow restriction (BFR) can elicit a similar acute training stimulus to that offered by either heavy REx or traditional low-load BFR REx. Method: Ten men completed trials with 30% one-repetition maximum (1RM) for 5 sets of 15 repetitions without BFR…

Volumetric titrations are an accurate and precise analytical method, which explains their use in industrial and research settings and their inclusion in senior secondary chemistry curricula around the world. Students often have difficulty understanding the intricacies of titrations because they are novices being presented with a long list of…

In this paper, we show a laboratory experience describing the possibility to build a sensor using a coil to measure small thicknesses of materials with the possibility of measuring temperature simultaneously, with the same built sensor. Its operation is based on the following facts: An electric current (a.c), flows through a coil and a magnetic…

Despite the recognized effectiveness of course-based undergraduate research experiences (CUREs), there are few examples of the development of a CURE-based course in a large-enrollment undergraduate organic chemistry laboratory. Herein, we describe the development and implementation of a series of undergraduate laboratory experiments centered…

We report on a simple, rapid, and room-temperature undergraduate-level experiment for gold nanoparticle synthesis, analysis, and utilization as a catalyst for the sodium-borohydride-assisted reduction of methylene blue and Congo red dyes. Typical procedures toward gold nanoparticle formation require an elaborate, lengthy synthesis (some requiring…

The concept of equilibrium vapor pressure plays a key role in the general chemistry curriculum; it is among the first and most easily demonstrated examples of equilibrium and frequently caps off the first semester of general chemistry where it illustrates the properties of liquids and intermolecular forces. We report here simple modifications of…

All-solid-state polymer electrolytes (SPEs) have been regarded as an advisible alternative for simultaneously overcoming the safety issues and high energy density demands presented in traditional lithium batteries, and they represent the development orientation of energy storage devices. This course describes the preparation of a cross-linked and…

Secondary metabolite compounds contained in each plant genus have certain characteristics, which is true also of the flavonoid in the genus "Artocarpus." In the experiment described here, third-year undergraduate students performed the isolation and characterization of cycloartocarpin from the roots of "Artocarpus altilis"…

According to the definition, surface tension could be affected not only by intermolecular interaction but also by molecular area. However, in chemistry textbooks, surface tension is mainly explained only in terms of intermolecular interaction. Although the existing surface tension concept in the textbooks can lead to a variety of counterexamples,…

The demand for sustainable synthetic methods has motivated the development of a myriad of strategies for substrate oxidation chemistry that reflect the goals of green chemistry. Here we present a two-part laboratory module that provides undergraduate chemistry students hands-on experience with the concepts of sustainable chemistry in the context…