In this work, we address the concept of the chemical potential [mu] in classical and quantum gases towards the calculation of the equation of state [mu] = [mu](n, T) where n is the particle density and "T" the absolute temperature using the methods of equilibrium statistical mechanics. Two cases seldom discussed in elementary textbooks are…

The Bohr-Sommerfeld quantum theory specifies the rules of quantization for circular and elliptical orbits for a one-electron hydrogen atom-like system. This article illustrates how a formula connecting the principal quantum number "n" and the length of the major axis of an elliptical orbit may be arrived at starting from the quantum…

Lectures are often thought of in terms of information transfer: students (do not) "get" or "construct meaning of" what physics professors (lecturers) say and the notes they put on the chalkboard (overhead). But this information transfer view does not explain, for example, why students have a clear sense of understanding while they sit in a lecture…

Green analytical chemistry principles were introduced to undergraduate students in a laboratory experiment focused on determining the mercury concentration in cow and goat milk. In addition to traditional goals, such as accuracy, precision, sensitivity, and limits of detection in method selection and development, attention was paid to the…

In a 4-h laboratory exercise, students accomplish a series of enzymatic macerations of apple mash, assess the viscosity of the mash during the maceration, extract the juice by centrifugation, and measure the levels of antioxidant phenols extracted into the juice after different enzyme treatments. The exercise shows the impact of enzyme-catalyzed…

IUPAC gives several different definitions of oxidation: loss of electrons, increase in oxidation state, loss of hydrogen, or gain of oxygen. Most introductory or general chemistry textbooks use all of these definitions at one time or another, which can lead to some confusion in the minds of first-year chemistry students. Some paradoxical…

A new method for obtaining Russell-Saunders terms of atomic configurations is reported. This new method is significantly different from, while at the same time complementary to, previously published methods for obtaining atomic terms. This novel procedure is elicited by the method used to determine the splitting of S, P, D terms in weak ligand…

This organic laboratory experiment introduces students to stereoselective enzyme reactions, resolution of enantiomers, and NMR analysis of diastereomers. The reaction between racemic 1-phenylethanol and vinyl acetate in hexane to form an ester is catalyzed by acylase I. The unreacted alcohol is then treated with a chiral acid and the resulting…

The surface plasmon wave is a surface wave confined at the interface between a dielectric and a metal. The excitation of the surface plasmon resonance (SPR) on a gold thin film is discussed within the Kretschmann configuration, where the coupling with the excitation light is achieved by means of a prism in total reflection. The electromagnetic…

Bertrand's paradox (Bertrand 1889 "Calcul des Probabilites" (Paris: Gauthier-Villars)) can be considered as a cautionary memento, to practitioners and students of probability calculus alike, of the possible ambiguous meaning of the term "at random" when the sample space of events is continuous. It deals with the existence of different possible…

We explored the impact of laboratory curriculum on students' understanding of the nature of science at five US universities. The specific curricula studied were traditional (verification), inquiry-based, and research-based. The inquiry curriculum was Inquiries into Chemistry, and the research-based curriculum was developed by the Center for…

For most materials, the solid at and near the triple-point temperature is denser than the liquid with which it is in equilibrium. However, for water and certain other materials, the densities of the phases are reversed, with the solid being less dense. The profound consequences for the appearance of the "pVT" diagram of one-component materials…

The acid ionization constant, K[subscript a], of acetic acid and the base ionization constant, K[subscript b], of ammonia are determined easily and rapidly using a datalogger, a pH sensor, and a conductivity sensor. To decrease sample preparation time and to minimize waste, sequential aliquots of a concentrated standard are added to a known volume…

Although the siphon has been in use since ancient times, the exact mechanism of operation is still under discussion. For example, most dictionaries assert that atmospheric pressure is essential to the operation of a siphon rather than gravity. Although there is general agreement that gravity is the motivating force in a siphon, there is…

To diversify the measurement techniques of Avogadro's number in physics teaching, I propose a simple acoustic method for the experimental determination of Avogadro's number based only on the measurement of the speed of sound in metals, provided that their Debye temperatures are known. (Contains 2 figures.)