Introducing High School Students to NMR Spectroscopy through Percent Composition Determination Using Low-Field Spectrometers

Abstract

Mole to gram conversions, density, and percent composition are fundamental concepts in first year chemistry at the high school or undergraduate level; however, students often find it difficult to engage with these concepts. We present a simple laboratory experiment utilizing portable nuclear magnetic resonance spectroscopy (NMR) to determine the percent composition in a series of household solutions explored with high school honors chemistry students. Students engage with the science by using a portable NMR spectrometer to acquire and process their own proton spectrum of rubbing alcohol. From the acquired data, students then used the aforementioned concepts and calculations to determine the percent composition of the mixture in wt/wt, and v/v percents. Students and teachers both expressed excitement with getting to work with “advanced” techniques and a better understanding of the relevance of stoichiometry, density, and percent composition.