Experimentação no ensino de células galvânicas utilizando o método Jigsaw

Abstract

Three experimental kits were developed to aid in the teaching of electrochemistry: galvanic cells, cells and batteries, and series and / or parallel associations. The kit were made from low cost and easy access materials and were used to teach concepts of electrochemistry, through cooperative learning using the jigsaw method. The students were divided into six groups of specialists (GE). Two experimental kits were prepared for each of the three subtopics of Electrochemistry: Experimental kit No. 1 - understanding the operation of commercial cells; Experimental kit No. 2 - understanding the operation of galvanic cells; and Experimental kit No. 3 - verifying the occurrence of reactions of oxidoreduction. Each subtopic was worked by two GEs. After the work, the GEs separated as pieces of a puzzle, and students formed the base groups (GB), each containing at least one expert from each subtopic. Six GBs were formed, each of which consolidated the learning of the three subtopics. A diagnosis was made of how the students evaluated the didactic activity and verified if the proposal helped to help students learn from the content worked. The research was carried out with the students of a group of the 2nd year of the High School of a Private College of Patrocínio, Minas Gerais and required 16 classes, of which 5 referred to the traditional method and 11 were designed for research and application of the jigsaw method. Questionnaires were applied before and after the didactic proposal. The groups' responses, in relation to the experimental kits, were grouped into three levels: "Incorporates", "Tangency" or "Distance". Considering the GEs, the experimental kit Nº. 1 had a high percentage of responses that incorporated and tainted the content, with about 86%, demonstrating a good use of the topic contemplated. For the experimental kit Nº. 2, about 89% of the responses incorporated and tainted the content addressed and, for the experimental kit Nº. 3, we had 100% of the answers classified as "Incorporates" and "Tangency", reflecting an excellent use of the contents covered in this group. When we add the answers classified as "Incorporates" and "Tangency", in relation to the GBs, we have for the experimental kit Nº. 1, 83% of the responses, for the experimental kit Nº. 2, 100% of the responses and for the experimental kit Nº. 3, 67% of the answers, demonstrating a high level of learning and interaction of the students that absorbed the knowledge from the GEs and shared through the GBs. The students' perceptions about chemistry, the jigsaw method and the experimental activities, respectively, were evaluated using the Likert scale, which indicated an excellent receptivity of the students in relation to the jigsaw method and the experimentation. We consider that the didactic proposal, besides motivating, helped the students' learning, providing good results, which consolidate the use of the jigsaw method, associated to experimental activities, in the teaching of galvanic cells.