Many chemistry laboratories are designed as one-week learning experiences focused on specific concepts and techniques. This segmentation often causes students to overlook the interconnection between chemistry concepts, laboratory techniques, and the overarching ideas of the laboratory curriculum. The work presented herein focuses on a multi-week interconnected laboratory design to foster clear connections between chemistry concepts (i.e., density, viscosity, and volume contraction) and the laboratory techniques. The laboratory work consisted of preparing binary mixtures of organic solvents (i.e., methanol, ethanol, isopropanol, and acetone) with water and determining the density and viscosity of the resulting solutions. Central to the laboratory design is the connection between the measurements, data collection, and binary systems’ properties. Thus, data gathered during the determination of density and viscosity are integrated to explain the observed volume contraction in the four binary systems. In particular, molecular volume (and shape) and intermolecular forces are critical concepts in constructing the explanation. Furthermore, molecular mechanics calculations were performed in Gaussian to determine the aqueous solutions’ physical properties and contrast the results against the empirical data. Laboratory procedures, data, and results will be presented and discussed in light of their design and implementation for chemistry laboratory programs.

Understanding density and viscosity of aqueous solutions in the chemistry laboratory

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.