Hydration of Decorative Beads: An Exercise in Measurement, Calculations, and Graphical Analysis

摘要

Throughout the general chemistry lab curriculum, a common shortcoming is the way in which students measure, record, and manipulate quantitative data. From initial measurements with different digital and analog instruments to proper conversions, calculations, and comparisons, students are often expected to be experts before they have been taught proper technique and scientific principles. While the start of any General Chemistry 1 course involves a period of familiarization with the scientific method, significant figures, and elements of atomic structure, these often do not correlate well with laboratory experimentation. We have developed an experiment to be conducted during the first weeks of a general chemistry lab that emphasizes measurement techniques, accuracy, average value calculations, and uncertainty of measurement calculations. The experiment is designed such that time versus mass change measurements are taken and used in an introduction to graphical analysis. This allows for the experiment to be done in a short period of time while also affording student-generated data for teaching spreadsheet use, data processing, and linear regression. Instructor feedback and student survey data following this experiment indicate significant improvement in students' abilities to collect and properly analyze data.