The imine condensation reaction is commonly addressed in second semester organic chemistry classrooms as imines and their derivatives are found in many pharmaceutical scaffolds and biological and catalytic processes. Despite this, imine condensations are still absent from many organic chemistry laboratory curriculums. The work discussed here…

Pulsed field gradient nuclear magnetic resonance (NMR) is used to estimate the size of quantum dots (QDs) produced in a simple, fast, small-scale synthesis. This upper-division laboratory experiment teaches the basics of QD synthesis and pulsed field gradient NMR, a powerful technique for measuring diffusion coefficients in solution. The diffusion…

To present the difference in oxidizing strength in concentrated and dilute nitric acid reacting with copper, a simple, facile demonstration of these reactions is designed using a waste plastic bottle, plastic droppers, and syringes, which are costless and easily assembled. This new version can be used to demonstrate the difference in oxidizing…

The coefficient of restitution (COR) for a collision is usually a number between 0 and 1 depending on whether the collision is completely inelastic, or perfectly elastic or something in between. That is the usual situation for colliding spheres or a ball dropped on a horizontal surface. A different situation arises when a bat collides with a ball.…

We describe a project implemented in the honors section of an upper-level analytical chemistry undergraduate course, in which students designed an experiment to compare the performance of two analytical techniques to determine the amount of ascorbic acid in a commercial sample. This project designed for 18 students is composed of three stages. In…

The impact force and duration when one billiard ball collides head-on with another is estimated by assuming that the balls are connected by a spring. The results are compared with a measurement when a billiard ball collides with a heavy, rigid surface.

The cannon boring experiment of Count Rumford, where eight kilograms of water were boiled by metal on metal friction, is investigated. Consideration of this dramatic demonstration can enrich classroom discussions of calorimetry, units of measure, elements, and thermodynamics. A section pertaining to use of the article in the classroom appears…

Categorizing the various levels of protein and nucleic acid structures is a relatively straightforward concept students understand quickly when shown representative structural images. However, keeping in mind the idea of primary, secondary, and tertiary structure proves more difficult when students are in the laboratory setting simply looking at a…

We discuss the limits of the equation of the period of a simple pendulum, T[subscript s] = 2[pi][square root]l/g, frequently used in high-school and university classrooms to measure the acceleration of gravity. We evaluate the relative error in determining the acceleration of gravity with this simple equation instead of a more realistic one,…

Progress is made in science by constructing many models (possibly of different complexities), testing them against measurements, and determining which of them explain the data the best. It is my observation, however, that in many introductory physics labs we provide students with the materials and methods to verify the "correct" model of…

So many fundamental physics problems involve rigid body rotation that mastery of the subject is essential to many science and engineering undergraduate degrees. Rigid body rotation is typically taught in introductory mechanics courses and while students are generally comfortable with the corresponding kinematic equations, torques and moments of…

The high level of consumption of processed foods has an effect on human health. The consumption of doughnuts, pastries, fried chicken, French fried potatoes, snack chips, and imitation cheese is high among teenagers. These foods are generally rich in fats, although the focus has often been on the quantity rather than the quality of these fats.…

We have revamped a classic analytical chemistry laboratory experiment, "Determination of an Unknown Acid", to provide students an opportunity to learn about new advances in the material sciences and their applications in analytical chemistry in an effort to reinforce the key concepts of chemical analysis. Specifically, students were…

In this paper, we present a physical modeling activity whose objective is to allow students to determine the differences between a disk and a sphere using pure scientific criteria. Thereunto, we reproduce the Sun-Earth-Moon system with low-cost materials and compare the illumination effects on the Moon considering two possible shapes for it (a…

A suitable combined laboratory experiment can involve more chemical disciplines and form students' views on practical connections. A laboratory experiment has been prepared focusing on the adsorption of the dangerous Co(II) ion using natural adsorbents representing waste material of a polysaccharide and keratin nature. Efficiency of Co(II)…