Selecting less hazardous chemicals is a core tenet of green chemistry but is difficult to teach in practice. The upper-year undergraduate or graduate level exercise described here empowers students to make such decisions themselves. Students are tasked with finding the greenest chemical for a specific purpose described in a hypothetical scenario, although the scenario provided in the example could easily be replaced by a scenario related to the instructor's interests or expertise. The scenario specifies the class of chemical (e.g., a trialkylamine), a performance requirement, a safety requirement, and two environmental or health impacts to consider. To complete the exercise, students must generate a library of structures using free molecular structure library-building software and predict the properties of those chemicals using quantitative structure-activity relationship (QSAR) software. Finally, the students review the predicted properties for select compounds that best match the design criteria. This exercise familiarizes students with QSARs and the concept of virtual screening and presents an opportunity for them to think critically about the selection of the greenest chemical for an application.