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…

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.…

The ability to extract structural information from a drawing of a molecule is key to being successful in organic chemistry. One source of difficulty for novices in interpreting structures is that hydrogens bound to carbon are represented implicitly in the often-used line-angle structures. Other representations that explicitly show hydrogens, such…

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…

Approximations can help to orient the student in an organic chemistry laboratory. There the student needs to develop the solvent systems for the reaction and isolation of organic reactants and products. The adage "like dissolves like" helps in this regard, but this approach is vague and entirely qualitative. More quantitative approaches…

Biochemistry students at the introductory level easily comprehend the importance of energy-yielding oxidation and reduction biochemical processes, but nevertheless, they fight with words "oxidation" and "reduction" (and with the corresponding adjectives, "oxidized" and "reduced") applied in biochemistry…

When structure-property relationships are discussed in inorganic chemistry and materials science, the common perception is that materials with the same composition and atomic arrangement have the same properties. In this laboratory experiment, we show that "processing"--the exact conditions under which materials are made--can in fact…

In this two-session experiment for an organic chemistry lab, students prepare a macrocyclic host compound--namely, a pillar[5]arene--by means of a templated 1,4-dimethoxybenzene/formaldehyde cyclo-oligomerization (session 1), and then, they explore its molecular recognition properties toward the 1,8-diaminooctane guest with the aid of [superscript…

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…

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…

High-resolution mass spectrometry (HRMS) is an analytical technique that is typically used by mass spectrometry experts. However, with recent advancements, it is becoming more accessible to students in organic chemistry laboratories. Still, a significant knowledge gap exists between these experts and students. A straightforward laboratory…

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…

We have developed a guided-inquiry laboratory exercise in which students perform viscosity measurements to infer the structure of poly(vinyl alcohol) (PVA) in aqueous solution. The activity combines both experiments and modeling. In the experimental portion of the exercise, students measure the viscosity of several solutions of PVA with differing…

Electrophilic aromatic substitution reactions are common in the organic chemistry laboratory. These reactions, while ubiquitous, use corrosive reagents and halogenated or hydrophobic solvents that produce expensive and hazardous waste streams. The carboxylation of phenols (Kolbe-Schmitt reaction), although aqueous, typically involves conditions…