标题：Green Chemistry in Action: An Undergraduate Experimental Project on the Quantitative Analysis of Bioethanol Blends with Synthetic Gasoline Using Natural Dyes
摘要：For the last eighty-five years, bioethanol was used as additive for gasoline in Brazil. Therefore, a project on the quantitative analysis of bioethanol-gasoline blends is timely and important. Using the constructivist approach, we introduced a project on this subject using green dyes, namely β-carotene and chlorophyll, selected by chemistry and pharmacy majors. We organized the project into the following steps: (i) We asked the students to do literature survey on the subject and to suggest natural dye(s) for quantitative analysis of bioethanol-gasoline blends. (ii) We gave a quiz on bioethanol, corrected it, and then discussed their answers in class. (iii) After performing the experiment, the students presented and discussed their data. (iv) The students evaluated the project. Both dyes were suitable for the purpose, and we used the data obtained to teach theory. The students’ evaluation indicated that they liked the constructivist teaching approach; their work in groups; and being a part of decision making of the experimental protocol.
