Modifications are presented for the iodine clock reaction to introduce the concept of activity and to help students better appreciate molecular aspects of chemical equilibrium. The addition of an unreactive salt affects the activity of the reactants in the iodine clock reaction. The difference in activity affects how long the iodine clock reaction…

As a widely applied theory that has found success across many fields, density functional theory (DFT) is largely taught. Typically, the most effective way to convey DFT concepts is through illustrative examples that are currently lacking in available resources. In this work, we demonstrate total energy calculations for H[subscript 2] using…

Benzoin, an [alpha]-hydroxy ketone, is stereoselectively reduced by sodium borohydride to yield hydrobenzoin, the stereochemistry of which is determined by acetalization and analysis of the derivative by NMR spectroscopy. This classical experiment has been enhanced by modern spectroscopic and computational analysis to enable students to…

In this paper, we develop a general but very simple mathematical foundation for the predefined coefficient graphical method of Hückel molecular orbital theory (HMO). We first present the general solution for the recurrence relation of the coefficients of Hückel molecular orbitals (MOs). Subsequently, for all the three unbranched hydrocarbons,…

The point particle is an idealized object where rotational and vibrational motion is ignored. Nevertheless, in many cases such degrees of freedom play a significant role. For example, the rotation and vibration of a molecule is an important "reservoir" of its internal energy. The excitation of these types of motion can occur during the…

Molecules and Computer: Chemistry Calculations in Class (MC[superscript 4]) is a computational laboratory intended for final-year high school or undergraduate students. The topic is the antioxidant potential of anthocyanidins, which is chemically related to their radical scavenging action via the mechanism of hydrogen atom transfer (HAT). This…

In multielectron atoms or molecules, quantized electronic energy states known as term states provide a framework for interpreting absorption and emission spectra. Enumerating the term states associated with any particular electron configuration is possible using time-honored procedures, but the underpinnings of the methods do not always receive…

The contemporary Human activity utilizes huge volumes of digital data to solve efficiently multiple socio-economic, scientific and technical problems. Now the big data analysis is mainly oriented to the socioeconomic sphere with a goal to lift the profit. The science and technology to penetrate deeper in the nature of objects and systems under…

Nitrogen gas dominates the Earth's atmosphere but is largely ignored. Molecular nitrogen is extremely stable and so nitrogen is termed inert. What would happen if another 'inert' gas were the dominant species instead of molecular nitrogen? Here we show how unique nitrogen is and how important it has been to life on planet Earth.

Electromagnetic radiation can be classified into two major types depending on its ability to detach electrons from atoms: ionising and non-ionising. The aforementioned categorization is significant due to the effects of ionising radiation on human tissue (e.g. carcinogenesis). However, many students around the globe cannot distinguish these two…

Torsional effects influence kinetic selectivity in a wide range of organic transformations. As such, textbooks commonly use Newman projections to illustrate the torsional effects that arise in their transition states. Unfortunately, these representations fall short when the reaction occurs "within a ring." In many cases, the torsional…

The VSEPR model has well-established limitations in its ability to represent accurate molecular and electronic geometries of simple molecules, which can create a significant need for students to relearn structure and bonding concepts in organic chemistry. We present an alternate method for describing molecular geometries and electronic structures…

A new undergraduate inorganic chemistry laboratory experiment is presented. An introduction of the spectrochemical series and ligand exchange is explored using the coordination complex dirhodium tetraacetate, Rh[subscript 2](OAc)[subscript 4]. Students have measured the absorption spectra of the Rh[subscript 2] complex in the presence of various…

Students collect magnetic susceptibility data to verify that Hund's rule correctly predicts electronic configurations. Systems examined include three commercially available lanthanide(III)-containing complexes of the form M(acac)[subscript 3](H[subscript 2]O)[subscript 2] (where M = La(III), Nd(III), and Gd(III), and acac denotes the [CH[subscript…

Activation energies form an energy barrier to a chemical reaction taking place. Simple collision theory, i.e. that particles need to collide to react, would suggest that activation energy is the energy needed to overcome a coulombic barrier provided by the negatively charged electrons contained within energy shells surrounding an atomic nucleus.…