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…

An activity of using waste plastic caps and wooden sticks (or steel wires) to construct crystal structures is described. Caps with different colors represent different atoms/ions/interstices, and sticks are employed to carry the caps and describe the positions of atoms/ions/interstices. The cap-and-stick model clearly demonstrates crystal…

A convenient approach to obtain Lewis structures for compounds of the type YX[subscript n] involves first constructing a trial structure that satisfies the valence of the outer atoms (e.g.,1 bond for fluorine, 2 bonds for oxygen, and 3 bonds for nitrogen)and placing the molecular charge (if any) on the central atom. The second step involves…

A chemistry laboratory experiment is described to introduce undergraduate college students to membrane separation technology. This experiment combines a simple nanowire membrane fabrication and visually indicated molecule separation. The membrane is produced via coprecipitation synthesis followed by a filtration assembly process, which can be…

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…

Valence shell electron pair repulsion theory (VSEPR) as explained in most textbooks predicts that substituents bonded to a central atom in AX[subscript n]E[subscript z][superscript c] species (A = main-group central atom, X = substituent, E = lone pair on central atom, c = charge) will change their X-A-X angles to bend away from the lone pairs.…

A new teaching resource comprised of raw X-ray diffraction data sets from crystallography experiments has been compiled. The aim of this resource is to provide a tool with which to plug the teaching gap between crystals and chemical structures present at various levels of education, as well as providing examples for early stage researchers and…

Climate change is a critical scientific and social issue of our time, yet the topic is not frequently discussed by the general public. Additionally, misconceptions about the topic persist. One important aspect of climate change is the greenhouse effect. This activity adds a greenhouse gas discussion to an existing module about molecular shape and…

Most chemistry instruction and assessment lie in the symbolic domain of Johnstone's representational levels, despite years of chemistry education researchers calling for increased emphasis to be placed on the molecular or particulate level of chemistry. Without a deep understanding of the particulate nature of matter and molecular-level…

The NMR spectrometer is a commonly used spectroscopic instrument that records resonance frequencies of nuclei present in molecular systems. While the NMR frequencies fall within the radio frequency regime for a given molecular system, they are presented in terms of chemical shifts in the audio frequency regime, thereby having the versatility to be…

A mixture of salt water and isopropyl alcohol is immiscible, forming two separate liquids with the organic layer on top and aqueous layer on bottom. When universal indicator is added to such a mixture, all of the indicator compounds in the universal indicator preferentially dissolve in the alcohol--except for phenolphthalein at high pH. Mixtures…

Magnetic molecular models help students explore molecular structures and interactions. In this study, we investigated how pairs of students used magnetic models to explore hydrogen bonding and the 6-fold symmetry of snowflakes. Fourteen first-year students enrolled in a chemistry unit participated in pairs. Students' interactions with the magnetic…

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…

Representations in chemistry are the tools by which students, instructors, and chemists reason with chemical concepts that are abstract. Although representations are regularly used within the chemistry classroom, there is more to uncover regarding the ways students interact with representations when given chemistry tasks. This study aimed to…

Single-molecule localization microscopy (SMLM) has revolutionized our ability to visualize cellular structures, offering unprecedented detail. However, the intricate biophysical principles that underlie SMLM can be daunting for newcomers, particularly undergraduate and graduate students. To address this challenge, we introduce the fundamental…