A Simple, Student-Built Spectrometer To Explore Infrared Radiation and Greenhouse Gases

作者：Bruce Mitchell R M^*; Wilson Tiffany A; Bruce Alice E; Bessey S Max; Flood Virginia J

来源：Journal of Chemical Education, 2016, 93(11): 1908-1915.

DOI：10.1021/acs.jchemed.6b00047

• High School/Introductory Chemistry
• First-Year Undergraduate/General
• Environmental Chemistry
• Laboratory Instruction
• Collaborative/Cooperative Learning
• Hands-On Learning/Manipulatives
• Inquiry-Based/Discovery Learning
• Internet/Web-Based Learning
• Problem Solving/Decision Making
• Laboratory Equipment/Apparatus

In this experiment, students build a spectrometer to explore infrared radiation and greenhouse gases in an inquiry-based investigation to introduce climate science in a general chemistry lab course. The lab is based on the exploration of the thermal effects of molecular absorption of infrared radiation by greenhouse and non greenhouse gases. A novel feature of the experiment has students building an infrared spectrometer, using a hot plate as an IR source, a sample compartment employing a plastic cuvette holder with open sides (to standardize the path length), and a low-cost infrared thermometer. Students, working in groups, (1) explore a PhET simulation; (2) design a set of experiments in response to a scientific question, "comparing the absorption of infrared light in the presence and absence of each different sample of gas, are there any significant differences that can be observed experimentally?"; (3) reflect on climate science and their experimental results by visiting the American Chemical Society Climate Science Toolkit; and (4) communicate their results in lab by constructing and presenting a poster. Assessment of student responses to a pre- and postexperiment question suggests that the lab has a positive influence on student understanding of the concepts involved in identifying greenhouse gases. Results postexperiment questions also provide information for what aspects of the online resources students found useful.