Chemistry

Thermotropic liquid crystal phases are ordered fluids found, for some molecules, at intermediate temperatures between the crystal and liquid states. Although technologically important, these materials typically receive little attention in the undergraduate curriculum. Here, we describe a laboratory activity for introductory organic chemistry students on the synthesis and characterization of the p-alkoxybenzoic acids. These compounds, through the formation of carboxylic acid dimers, exhibit liquid crystal phases common in rod-like (calamitic) molecules.

The high-performance liquid chromatography (HPLC) experiment, most often done in the undergraduate analytical instrumentation laboratory course, generally illustrates reversed-phase chromatography using a commercial C₁₈ silica column. To avoid the expense of periodic column replacement and introduce a choice of columns with different stationary phases, we have developed an experiment in which students prepare and test a polymer-based monolithic column. The 10 or 15 cm monolithic column is prepared using 1/8 in. o.d. × 2.3 mm i.d. poly(ether ether ketone) or PEEK tubing.

The Chemistry Education Research (CER) Doctoral Scholars Program trains a diverse group of graduate students how to develop assessments of secondary and tertiary students’ understandings of core concepts in chemistry.

The goal of this project was to create an inquiry activity to teach symmetry elements and symmetry operations in an inorganic chemistry course. Many students experience difficulty when building and mentally manipulating three-dimensional mental models from two-dimensional images, causing difficulty when learning symmetry. Process-oriented, guided-inquiry learning (POGIL) was used to structure the activity using a learning cycle paradigm consistent with research on how students learn as described by Novak’s human constructivism theory.