Observing and measuring the macroscopic world in freshmen chemistry lab

CHED 429

Scott J. Donnelly, scott.donnelly@azwestern.edu, Department of Chemistry, Arizona Western College, 9500 South Avenue 8E, PO Box 929, Yuma, AZ 85366
How can students understand the microscopic world when they have difficulty observing and then offering plausible explanations for macroscopic phenomena? In this presentation the author will discuss labs that take students outdoors to measure the world as it is and not how we perhaps want it to be in the controlled environment of test tubes or sterile computer simulations. The presentation will include but is not limited to discussion of labs developed that use: 1) light meters and colored plastic paddles to give a qualitative understanding of incident solar radiation, 2) constant velocity sticks to measure and graphically represent the viscosity of unknown liquids, and 3) an elemental analyzer and portable quantum (Photosynthetic Photon Flux or PPF) meters to determine the theoretical volume of cellulosic ethanol derived from the post-harvest of an acre of Durham wheat. Methods used to assess student learning in each lab will be woven into the presentation.