In this article, we describe how to develop an inductive metal detector that can be integrated to any Android or iOS smartphone with a standard audio port at low cost. The results indicate the metal detector can be used in the physics teaching laboratory as a practical application of principles of electromagnetism. It allows one to differentiate…

In a recent "AstroNote," I described a simple exercise on the mass-luminosity relation for main sequence stars as an example of exposing students in a general education science course of lower mathematical level to the use of quantitative skills such as collecting and analyzing data. Here I present another attempt at a meaningful…

A set of biochemistry experiments based on the technique of protein colorimetry is described. Students used the Biuret and Bradford assays to qualitatively and quantitatively assess solutions for protein. Two unique features of these experiments are (1) the use of intentional discrepancies within each experiment to promote critical thinking and…

There is a growing movement to involve undergraduate students in authentic research experiences. A variety of studies have indicated the strength of this approach in developing scientific aptitude, confidence, critical thinking skills, and increasing the likelihood to become career scientists. Course-based undergraduate research experiences…

In this paper, we report an experiment intended as a tool to introduce chemistry and materials science students to several chemical concepts through the determination of the best experimental conditions for the formation of calcium oxide (lime) from a source of high content of calcium carbonate (eggshells). Thermal gravimetric analysis (TGA),…

We report here a method that utilizes the vapor pressure of HCl(g) above a concentrated HCl(aq) solution as an extremely simple and safe method to produce small amounts of HCl vapor in an IR gas cell. This vapor pressure approach can also be used to produce DCl(g) by introducing a few drops of concentrated DCl(aq) into the gas cell.

Adsorption of methylene blue and malachite green was carried out using "Luffa cylindrica" sponges as adsorbing material. We provide a very illustrative exercise about the use of common natural materials requiring little preparation to solve environmental tasks in a routine laboratory situation such as using dyes. In addition, the…

To inspire upper-division undergraduate students to gain a deeper understanding of biorefinery, an experiment related to biofuels and lignin-based sunscreen products from corncob was performed in multiple offerings of a summer-semester class. Specifically, corncobs were pretreated with 1% H[subscript 2]SO[subscript 4] to obtain hemicellulose…

A new laboratory experiment investigating the ternary phase equilibrium of water-propan-2-ol-sodium chloride with one-, two-, and three-phase regions has been developed. Observations of the type and number of phases of a series of mixtures of the three components were made, and the results are then used in a systematic way to more finely choose…

An experiment involving a moisture-sensitive synthesis and spectroscopic characterization suitable for the advanced inorganic laboratory course is presented. The acid-base complex ammonia borane (AB) is synthesized from the heterogeneous reaction between sodium borohydride and finely ground ammonium sulfate in tetrahydrofuran solvent. AB is…

The different reactivities between 1°, 2°, and 3° butyl chlorides by the unimolecular nucleophilic substitution (S[subscript N]1) mechanism were easily observed at 60 °C by a solvolysis reaction in ethanol with ether formation. The hydrogen ion from the byproduct HCl reacted with an acid--base indicator such as methyl red to induce a color change.…

An experiment for the upper-division undergraduate biochemistry laboratory is described in which students investigate the influence of genetic variations of cytochrome P450 1A2 on drug metabolism, using caffeine as a model compound. Saliva samples from human subjects are characterized for a single-nucleotide polymorphism in the CYP1A2 gene…

Reported herein is a multidisciplinary laboratory experiment for advanced undergraduate students that includes elements of material synthesis, in the synthesis of cyclodextrin-containing metal-organic frameworks (CD-MOFs), and environmental chemistry, in the use of these MOFs for pollutant removal. This multiday laboratory experiment starts with…

Newton's laws of mechanics are a cornerstone in the development of modern science and its learning can be the very first opportunity for students to defy their common sense perceptions and replace them with a more robust world view. However, despite their fundamental importance, many studies demonstrate how difficult is the true comprehension of…

Disrupting a gene to determine its effect on an organism's phenotype is an indispensable tool in molecular biology. Such techniques are critical for understanding how a gene product contributes to the development and cellular identity of organisms. The explosion of genomic sequencing technologies combined with recent advances in genome-editing…