Suzuki couplings are powerful chemical reactions commonly employed in academic and industrial research settings to generate functionalized biaryls. We have developed and implemented a discovery-based, microscale experiment for the undergraduate organic chemistry laboratory that explores green Suzuki coupling using water as the primary solvent.…

Worldwide, more than 85% of all chemical products are manufactured with the help of catalysts. Virtually all transition metals of the periodic table are active as catalysts or catalyst promoters. Catalysts are divided into homogeneous catalysts, which are soluble in the reaction medium, and heterogeneous catalysts, which remain in the solid state.…

A simple and inexpensive mercury-free apparatus to measure the change in volume of a gas as a function of pressure at different temperatures is described. The apparatus is simpler than many found in the literature and can be used to study variations in pressure, volume, and temperature. (Contains 1 table and 7 figures.)

Numerous articles have been published that address problems encountered in teaching basic concepts of chemistry such as the atomic mass unit, Avogadro's number, and the mole. The origin of these problems is found in the concept definitions. If these definitions are adjusted for teaching purposes, understanding could be improved. In the present…

A laboratory experiment is described to determine the primary current distribution in parallel-plate electrochemical reactors. The electrolyte is simulated by conductive paper and the electrodes are segmented to measure the current distribution. Experiments are reported with the electrolyte confined to the interelectrode gap, where the current…

We propose the use of Tracker, freeware for video analysis, to analyse the moment of inertia ("I") of a cylindrical plate. Three experiments are performed to validate the proposed method. The first experiment is dedicated to find the linear coefficient of rotational friction ("b") for our system. By omitting the effect of such friction, we derive…

A simple, effective demonstration of the concept of limiting and excess reagent is presented. Mixtures of either air/methane (from a gas line) or air/butane (from a disposable cigarette lighter) contained in a plastic 2 L soda bottles are ignited. The mixtures combust readily when air/fuel ratios are stoichiometric, but not at a 2-fold excess of…

Photography is one of the few fine art forms that were initially developed by scientists such as Herschel and Talbot; however, in the modern chemistry curriculum, photography has become divorced from its scientific beginnings and resides in the studio arts department of most universities. An upper-level undergraduate experiment is described in…

The introduction of modern high-speed cameras in physics teaching provides a tool not only for easy visualization, but also for quantitative analysis of many simple though fast occurring phenomena. As an example, we present a very well-known demonstration experiment--sometimes also discussed in the context of falling chimneys--which is commonly…

Berry's phase, although well known since 1984, has received little attention among textbook authors of solid state physics. We attempt to address this lack by showing how the presence of the Berry's phase significantly changes a standard concept (effective mass) found in most solid state texts. Specifically, we show that the presence of a non-zero…

Three different samples of students were asked to answer five multiple-choice questions concerning the properties of a sample of helium gas (particle speed, state of matter, sample volume, sample pressure, and particle distribution), including a particulate question first used by Nurrenbern and Pickering (particle distribution). In the first…

We propose a simple and fascinating experiment for studying diffusion in gels using a pH-sensitive dye. By doping agar with methyl red, we obtain a gel which rapidly reacts to changes in pH by changing its absorption spectrum. The pH gradients can be followed using a digital camera, and we demonstrate here that the pH-sensitive colour changes can…

Two challenges faced by university instructors in introductory chemistry courses are the need to keep the course material connected with technology that students are using as well as engaging students in a manner that keeps them interested in the subject. A case study is described where students in a general chemistry course were challenged to…

The screened Coulomb potential, or Yukawa potential, is used to illustrate the application of the single and linear variational methods. The trial variational functions are expressed in terms of Slater-type functions, for which the integrals needed to carry out the variational calculations are easily evaluated in closed form. The variational…

The purpose of this laboratory experiment is to introduce aspects of materials chemistry, such as polymers and nanoparticle synthesis and properties, to students by their fabrication of a take-home polydimethylsiloxane window cling containing gold or silver nanoparticles. This lab covers small portions of three successive laboratory periods and is…