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…

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…

Environmental pollution is both a worldwide and a local issue, and microplastic pollution in particular is receiving increased attention due to its prevalence and bioaccumulation potential affecting the food chain. This laboratory experiment uses current, research-based methods such that the students can determine the extent of microplastic…

Facing calls for greater emphasis on STEM education in primary school classrooms, teachers may be anxious because of limited exposure to STEM in their own education. The Australian Curriculum: Technologies is new and many teachers are not familiar with its content. Hence both in-service and pre-service teachers (PSTs) require preparation. This…

This research reports the assessment of pre-service teachers' reception and attitudes towards virtual laboratory experiments in Life Sciences with the aim of advancing adaptability to digital learning. Using sequential mixed-methods in a quasi-experimental design, 68 pre-service teachers in the 3rd year of a Bachelor of Education (B.Ed) program…

Three days into the academic year, the COVID-19 pandemic abruptly led to emergency remote teaching, ERT, of Chemical Experimentation--a revised alternative to the majors' General Chemistry Laboratory at the University of Costa Rica. The course was reoriented to support students' development of nontechnical experimentation skills and scientific…

Photochemical synthesis, in which light is used as an indispensable reagent, is recognized as a green technique for organic synthesis and has been paid extensive attention. In this laboratory experiment for chemistry classes, a photoinduced C-C coupling reaction is introduced, which can be conducted under mild conditions at room temperature.…

Based on a publication of Assis, where the most straightforward and oldest motor is described, first constructed by Ampère, a simple experiment is added to demonstrate once again, why published explanations about its principle of operation and especial the kind how Newton's 3rd principle is used has to be rejected. Ampère's description of his…

In this article, the dynamics of a traditional toy, the yo-yo, are investigated theoretically and experimentally using smartphone sensors. In particular, using the gyroscope the angular velocity is measured. The experimental results are complemented thanks to a digital video analysis. The concordance between theoretical and experimental results is…