The area of application of electrospray ionization mass spectrometry (ESI-MS), usually coupled with liquid chromatography, seems to be much larger than those of any other ionization method. It gives rise to the demand for new teaching methods that would effectively help students to master the principles of working with and making full use of the…

In this two-session experiment for an organic chemistry lab, students prepare a macrocyclic host compound--namely, a pillar[5]arene--by means of a templated 1,4-dimethoxybenzene/formaldehyde cyclo-oligomerization (session 1), and then, they explore its molecular recognition properties toward the 1,8-diaminooctane guest with the aid of [superscript…

Benzoin, an [alpha]-hydroxy ketone, is stereoselectively reduced by sodium borohydride to yield hydrobenzoin, the stereochemistry of which is determined by acetalization and analysis of the derivative by NMR spectroscopy. This classical experiment has been enhanced by modern spectroscopic and computational analysis to enable students to…

We have developed a guided-inquiry laboratory exercise in which students perform viscosity measurements to infer the structure of poly(vinyl alcohol) (PVA) in aqueous solution. The activity combines both experiments and modeling. In the experimental portion of the exercise, students measure the viscosity of several solutions of PVA with differing…

This study proposes a lab experiment consisting of three consecutive steps designed to expose undergraduate students to the fundamental aspects of nanoscience. Two different procedures for the reduction of silver ions were provided: Th was obtained. Next, the students explored the aggregation process of silver nanoparticles by converting one…

The classic silver mirror reaction at room temperature in textbooks usually used glucose to react with silver nitrate and ammonium nitrate with the presence of caustic alkalis. But the aldehydes such as acetaldehyde and propionaldehyde were difficult to react under the same condition. In this paper, Na[subscript 2]CO[subscript 3] was used to…

The crystalline sponge method allows for direct and precise molecular structure determination of liquid and gaseous targets and thus has been recognized as a revolutionary breakthrough in crystallography. To expose undergraduates to this cutting-edge technique, we have developed a comprehensive laboratory experiment with reaction conditions and…

An understanding of basic organic chemical reactivity is key for many biosciences students. The reactivities of different carbonyl groups affect their function in many biomolecules. A practical class, the two-step synthesis of paracetamol, has been devised to illustrate the electrophilic reactivities of carbonyls, which was covered in the…

Why do we need to pour less water in an egg steamer to prepare more eggs to the same degree of 'doneness'? We discuss the physical processes at work in the electric egg steamer and resolve this seeming paradox. We demonstrate that the main heat transfer mechanism from steam to egg is due to latent heat through condensation. This not only explains…

An absorption line at 900 nm has been observed in Perspex. Samples of 1 and 2 cm thickness were used and the integrated absorption (line width times peak absorption) of the line was proportionate to the thickness. Facilities for lowering the sample temperature were not available and therefore both measurements were carried out at room temperature.…

Using crystal structure data, site directed mutagenesis, and real-time kinetic assays, students designed, expressed, and purified engineered mutants of human insulin-degrading enzyme (IDE). Students designed their own IDE mutants following "in silico" analysis, used inverse PCR to generate mutant plasmid expression constructs, expressed…

The aim of this study was to develop molecular genetics inquiry programs using the "eyes absent" gene of "Drosophila melanogaster." The program was composed of various molecular genetics experiments, including mutation observation, cross-breeding, searching for genetic information in web databases, gDNA extraction, and PCR.…

The question from the title is raised because in almost all introductory physics courses/textbooks the atmospheric pressure has been attributed to the weight of the column of air from a given level in the atmosphere up to its top. "Air is pressing on air." However the same textbooks, in the chapter on the kinetic theory of gases, tell…

The article describes a new version of a demonstration experiment for the Maxwell distribution. In the first part students analyse the applicability of the Gaussian distribution to the projection of the particle velocities in the suggested experiment. Further, students observe two-dimensional distribution of particles by the modulus of velocity in…

Surface chemistry impacts technology, advancing the development of new heterogeneous catalysts, semiconductor devices, and materials synthesis. Carbon surfaces are ubiquitous in various fields, and the surface reactivity can be altered by surface functionalization on the molecular scale, introducing functional groups, thus shifting their…