Three variants of the rotational viscometer employing a dc motor are considered. The viscometers are highly suitable for liquids of high viscosity, such as glycerol or oils (that is, for [eta] in the range 10-1000 mPa s). The set-ups are very simple and can serve as a first step to designing devices that are more complicated. Experimentation with…

A multidisciplinary experiment has been developed in which students each synthesize a combinatorial library of 48 hydrazones with the aid of a liquid-handling robot. Each product is then subjected to a Kirby-Bauer disk diffusion assay to assess its antibacterial activity. Students gain experience working with automation and at the…

Pharmacists, although not practicing chemists, often use skills and knowledge obtained in chemistry courses that are essential for success in their profession. This is especially apparent when preparing prescriptions for drugs that do not have a commercially available dosage form. Some well-publicized events indicate the potency of these drugs is…

Inexpensive electrodes for the measurement of pH have been constructed using the ionophore tribenzylamine for sensing H[superscript +] concentrations. Both traditional liquid-membrane electrodes and coated-wire electrodes have been constructed and studied, and both exhibit linear, nearly Nernstian responses to changes in pH. Measurements of pH…

Differential scanning calorimetry analyses of two easily prepared polymorphs of acetaminophen (also known as paracetamol) are recorded. The density of the forms can be found in the literature. Rules for heats of transition, heats of fusion, and density, as well as methods for determining the solid-solid transition temperature between the forms,…

Kinetic study on the hydrolysis of diphenylbromomethane does not provide clear-cut evidence for the mechanism of the reaction. The reduction in the rate of the reaction by added bromide ions suggested that the reaction took place by a S[subscript N]1 mechanism. A more detailed study of this common-ion effect, using conductivity to measure the rate…

We present an analysis on the locus formed by the set of maxima of the trajectories of a projectile launched in a medium with linear drag. Such a place, the locus of apexes, is written in terms of the Lambert "W" function in polar coordinates, confirming the special role played by this function in the problem. To characterize the locus, a study of…

It is well known that the speed [image omitted] is obtained in the process of defining SI units via action-at-a-distance forces, like the force between two static charges and the force between two long and parallel currents. The speed c[subscript u] is then physically different from the observed speed of propagation c associated with…

Two experiments related to standing sound waves in air are adapted for using the ScienceWorkshop data-acquisition system with the DataStudio software from PASCO scientific. First, the standing waves are created by reflection from a plane reflector. The distribution of the sound pressure along the standing wave is measured. Second, the resonance…

Whether it is a rapid-fire Twitter event as part of #ASEchat, or BBC Radio 4's "Inside Science," the discussion of practical work generates powerful debate. While it is right that the best use of practical work is continually discussed, its value in science teaching is without question. The level of discussion is being further heightened…

This study reports on a content course for science immersion teacher candidates that emphasized authentic practice of science and thinking scientifically in the context of introductory astrophysics. We explore how 122 science teacher candidates spanning three cohorts did and did not reason scientifically and how this evolved in our program. Our…

We selected diabetes mellitus for this laboratory exercise to provide students with an explicit model for scientific research concerning the association between the R230C polymorphism and susceptibility to type 2 diabetes mellitus, which is highly prevalent in the Mexican population. We used a collaborative project-based learning to engage…

I present a witty solution in this article about how we may obtain data simply and cheaply from physical experiments, with which we can do counting, as well. To this interdisciplinary task I turn to Delphi for help, in which we can program a digital video as a multimedia element. I show an example from the programming of plain multimedia elements…

At Miami University in Oxford, Ohio, the second-semester general chemistry course for chemistry majors is the equivalent of an analytical laboratory course. The experiments in the course are classified as classical, discovery, or instrumental on the basis of their structure and purpose. To investigate students' perceptions of learning through…

Chia seeds will sprout on almost any moist surface, and they respond quickly to experimental variables. Furthermore, the newly recognized nutritional value and rich cultural history of chia seeds offer the possibility of highly motivating and educational interdisciplinary extensions, especially appropriate to students in the middle grades.…