The relative acidities of water and methanol have been a nagging issue. In gas phase, methanol is more acidic than water by 36.0 kJ/mol; however, in aqueous solution, the acidities of methanol and water are almost identical. The acidity of an acid in solution is determined by both the intrinsic gas-phase ionization Gibbs energy and the solvent…

Following on from our previous article (Oon and Subramaniam 2009 "Phys. Educ." 44 384-91), here we trace ideas on the history of light from the Planck era to modern times. In particular, the seminal contributions of Planck, Einstein and de Broglie are highlighted. Some lesser known facets of the nature of light are also emphasized. It is stressed…

In this paper we present an analysis of chemistry texts (mainly textbooks) published during the first half of the 20th century. We show the evolution of the explanations therein in terms of atoms and of atomic structure, when scientists were interpreting phenomena as evidence of the discontinuous, corpuscular structure of matter. In this process…

A major approach for implementing green chemistry is the discovery and development of synthetic strategies that reduce the quantity of solvent needed, eliminate it altogether, or rely on new reaction media. An increasing number of examples have demonstrated that greener reaction solvents or media can enhance performance as well as reduce hazard.…

Cellular processes that rely on knowledge of molecular behavior are difficult for students to comprehend. For example, thorough understanding of meiosis requires students to integrate several complex concepts related to chromosome structure and function. Using a grounded theory approach, we have unified classroom observations, assessment data, and…

The generally accepted method to determine iron content in food is by acid digestion or dry ashing and subsequent flame atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. We have developed an experiment that chemically extracts the iron from an egg yolk and quantifies it using UV-vis absorption…

Diapocynin (5,5'-dehydrodiacetovanillone) was synthesized by oxidative coupling of apocynin (acetovanillone, or 4-hydroxy-3-methoxyacetophenone). Diapocynin is a metabolite of apocynin, which has anti-inflammatory and anti-oxidative properties. The oxidizing agent was an in situ generated sulfate radical, produced by adding iron(II) sulfate and…

The original use of the prefix "meso" was to refer to an optically inactive, non-resolvable member of a set of stereoisomers, some of which were optically active. More recently there have been attempts to define meso in terms of the structural features that can account for the existence of meso forms. It is unlikely that an effort of this kind…

In this article I review one of the most significant accomplishments of Frank H. Westheimer, one of the most respected chemists of the 20th century. This accomplishment was a series of stereospecific enzymatic oxidation and reduction experiments that led chemists to recognize what we now call the enantiotopic and diastereotopic relationships of…

As part of the SMATHematics Project: The Wonder of Science, The Power of Mathematics--a collaborative partnership between Kennesaw State University and two local school districts, fifth graders had the opportunity to puzzle out chemical formulas of propane, methanol, and other important molecules. In addition, they explored properties that…

A short history of chemical shifts in nuclear magnetic resonance (NMR), electron spectroscopy for chemical analysis (ESCA) and Mossbauer spectroscopy, which are useful for chemical studies, is described. The term chemical shift is shown to have originated in the mistaken assumption that nuclei of a given element would all undergo resonance at the…

Decades ago Buerger described and later Palmer reviewed stuffed silica crystal structures widely used by mineralogists. Many publications and books have discussed common crystal structures in terms of close-packing of one set of atoms or ions (P sites) with other atoms or ions in tetrahedral (T) or octahedral (O) sites. Douglas and Ho described…

A highly simplified model for helium dimers that reproduces their essential features without the need for elaborate computation is presented. The He-He potential is predicted to have minimum of 10.9 K at a nuclear separation of 5.61 bohrs.

Understanding the normal mode vibrations of a molecule is important in the analysis of vibrational spectra. However, the complicated 3D motion of large molecules can be difficult to interpret. We show how images of normal modes of the fullerene molecule C[subscript 60] can be made easier to understand by superimposing them on images of the normal…

We present calculations of ion-atom collisions using a partial-wave expansion of the projectile wavefunction. Most calculations of ion-atom collisions have typically used classical or plane-wave approximations for the projectile wavefunction, since partial-wave expansions are expected to require prohibitively large numbers of terms to converge…