The self-association of caffeine in solution, driven by the hydrophobic effect, is a simple example of molecular aggregation. It obeys an isodesmic association model in which each successive binding occurs with the same equilibrium constant. Here, we describe an activity for chemistry students that explores this phenomenon using nuclear magnetic…

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…

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…

NMR prediction using ChemDoodle, NMR calculation with Gaussian, and hands-on data collection using a benchtop NMR spectrometer were explored to assess their synergistic capacity in teaching NMR to organic chemistry students. Nine molecules representing functional groups commonly encountered in undergraduate organic chemistry were selected. Spectra…

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…

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…

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 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…

Iodonium zwitterions are hypervalent iodine compounds in which the iodine center binds to two substituents and carries a positive formal charge which is compensated by a negative charge within the same molecule. Under thermodynamic conditions, iodonium zwitterion sallow concerted nucleophilic aromatic substitutions to be performed, followed by…

This is an easy and cheap experiment where chemistry Masters students can evaluate the role of some metal ions (i.e., Cu[superscript II] and Mn[superscript II]) in dopamine oxidation, related to Parkinsonism. The required prior knowledge is being familiar with the basis of UV-vis spectroscopy. Details of the activity, including procedure and…

In this article we consider a well-known simple, very accessible demonstration of surface tension with a small boat propelled by substances that change the surface tension of water. A simple quantitative evaluation is provided that matches well with experimental data. A modification to the experiment is proposed allowing it to continue for a long…

Polymers and nanochemistry are important facets of chemistry. In this experiment, students synthesize monodispersed poly(methyl methacrylate) nanospheres from the addition or chain polymerization of a rapidly stirred aqueous mini-emulsion of methyl methacrylate. The 2,2'-azobis(2-methylpropionamidine) dihydrochloride serves as a heat activated,…

We present the use of an oxygen tolerant controlled radical polymerization (photoinduced electron/energy transfer-reversible addition fragmentation chain transfer polymerization, PET-RAFT) as a simple method for preparing controlled radical polymers in an undergraduate laboratory. Unlike conventional techniques, PET-RAFT polymerizations require no…