Integration of a water quality laboratory sequence into a core chemistry course

Abstract

According to the President's Council of Advisors on Science and Technology, less than 40% of students entering college intending to major in STEM-related fields graduate with a STEM degree. High-performing students frequently credit uninspiring introductory courses for their change in direction. Introductory courses in the Department of Chemistry and Life Science at the United States Military Academy include two semesters of general chemistry. General Chemistry II is a core chemistry course required for Chemical Engineering, Chemistry, Kinesiology, Life Science, Environmental Engineering, Environmental Science and Mechanical Engineering majors; students preparing for medical school; or as a science elective. The roughly 200 students enrolled each semester are divided into sections of approximately 20 students taught by 6 faculty members. To improve student engagement in General Chemistry II, a research inspired, water quality themed laboratory sequence was implemented beginning in the Spring 2017 semester. The water quality laboratory sequence consists of four introductory skill-building labs followed by three labs during which students tour a water treatment facility, then collect and analyze water samples of their choice. Students collect samples from water sources near the student living area, to include treated tap water, an estuary, and a reservoir. Examples of water quality analyses students complete include titrimetric methods, which are applied to measure parameters such as total hardness and total alkalinity; and UV-Vis spectroscopy to measure dissolved iron. The goal of the new laboratory sequence was to implement the following key elements: (1) support content goals of the course; (2) be hands-on; (3) balance expository and inquiry-based instruction; (4) be feasible to implement with available resources; and (5) promote a constructive affective learning environment. The first four elements listed above were assessed based on alignment with course learning objectives and American Chemical Society guidelines and analysis of the data generated by students in the laboratory. The final element was assessed based on feedback from students. More than half of the students surveyed each semester reported the lab sequence increased their level of interest in pursuing research in a STEM field. These preliminary findings suggest the water quality themed lab sequence was successful in improving student engagement and maintaining or increasing level of interest in STEM-related fields.