A procedure for the study of structural differences and intermolecular attraction between ethanol and 1-butanol based in laboratory work is described. This study provides comparisons of data retrieved from both a determination of boiling point and gas chromatography traces for the mixture. The methodology reported here should provide instructors…

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…

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…

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…