Lesson plan of Electrochemistry: Electrolysis

Objectives (5 - 7 minutes)

1. Understand the concept of electrolysis and its practical application in everyday life, highlighting the process of decomposing compounds by passing electric current through them.
2. Identify the basic components of an electrolytic system (anode, cathode, electrolyte) and understand the role of each in the electrolysis process.
3. Apply Faraday's laws to calculate the amount of substance produced or consumed in an electrolysis reaction, recognizing their relevance in the industry.

Secondary objectives:

1. Stimulate students' critical thinking and problem-solving skills through practical activities and consolidation exercises.
2. Develop teamwork skills by encouraging discussion and debate on the concepts and applications of electrolysis.
3. Apply the knowledge acquired in everyday situations, promoting interdisciplinarity and contextualization of the content.

Introduction (10 - 15 minutes)

1. Review of previous concepts: The teacher should begin the class by reviewing fundamental concepts for understanding electrolysis, such as the definition of ions, the concept of electrical conductivity, and the difference between oxidation and reduction reactions. This review can be done quickly, through direct questions to the students. (3 - 5 minutes)

2. Problem situations: To arouse students' interest, the teacher can present two problem situations related to the theme of the class. The first may be the question of how the silver from a cutlery rusts even if it is in contact with water, and the second may be the question of why the iron in a nail is the first part to rust. These situations serve to introduce the concept of electrolysis and instigate students' critical thinking. (3 - 5 minutes)

3. Contextualization of the theme: The teacher should then contextualize the importance of electrolysis, explaining that this process has several practical applications in everyday life and in the industry. It can be mentioned, for example, the electrolysis used for the production of aluminum, the galvanization of metals, the anodization of aluminum, among others. (2 - 3 minutes)

4. Introduction of the topic: Then, to introduce the topic of the class, the teacher can share two curiosities or stories related to electrolysis. The first one could be the story of how electrolysis was discovered by Alessandro Volta in 1800, when trying to understand why two different metals in contact with skin produced a tingling sensation. The second curiosity could be the modern application of electrolysis in the production of hydrogen, a clean and renewable source of energy. (2 - 3 minutes)

Development (20 - 25 minutes)

1. Practical Activity "The Electrolytic Cell": The teacher should divide the class into groups of up to 5 students. Each group will receive an electrolytic cell assembly kit, containing a direct current source, connecting wires, copper and zinc electrodes, and a copper sulfate solution. The objective of the activity is to assemble the electrolytic cell, observe the electrolysis reaction occurring, and record the changes that occur in the electrodes and in the solution over time. During the activity, the teacher should circulate around the room, assisting the groups, clarifying doubts and stimulating reflection on what is being observed. At the end of the activity, the teacher should promote a class discussion, questioning the students about the observations made, the changes in the electrodes, the formation of ions, and the transfer of charge. (10 - 12 minutes)

2. Problem-solving activity "Faraday's Laws": Then, the teacher should propose a series of problems applying Faraday's laws. The problems should involve the calculation of electric charge, number of moles of a substance produced, and mass of a substance produced in an electrolysis reaction. The students, still in their groups, should discuss and solve the problems. The teacher should circulate around the room, assisting the groups, clarifying doubts and verifying the students' understanding of Faraday's laws. At the end of the activity, the teacher should correct the problems together with the class, clarifying any doubts that arise and reinforcing the concepts worked on. (8 - 10 minutes)

3. Fun activity "Electrolysis Quiz": To end the Development stage of the class, the teacher should propose a question and answer game about electrolysis, using a quiz application or cards with questions. The objective is to review the concepts learned in a fun and enjoyable way. The teacher should divide the class into teams and award the team that gets the most correct answers. During the game, the teacher should clarify any doubts that arise and reinforce the concepts worked on. (2 - 3 minutes)

Feedback (10 - 12 minutes)

1. Group Discussion (3 - 5 minutes): The teacher should promote a group discussion with all the students, where each group will have the opportunity to share the conclusions and solutions found during the activities. Each group will have a maximum of 3 minutes to present their observations and reflections. During the presentations, the teacher should stimulate interaction between the groups, encouraging questions and comments.

2. Connection with Theory (3 - 4 minutes): After the presentations, the teacher should make the connection between the practical activities and the theory presented in the Introduction of the class. The teacher should highlight how the concepts of electrolysis, the formation of ions, the transfer of charge, and Faraday's laws were applied and observed during the activities. This contributes to the consolidation of learning and to the understanding of the relevance of theoretical concepts in practice.

3. Individual Reflection (2 - 3 minutes): To conclude the class, the teacher should propose that each student reflect individually on what was learned. The teacher can ask questions like: "What was the most important concept you learned today?" and "What questions have not yet been answered?" The students will have a minute to think and then the teacher may ask some students to share their answers with the class. This reflection activity helps students to consolidate what was learned, identify possible gaps in understanding, and promote self-assessment of their own learning.

4. Teacher Feedback (1 - 2 minutes): Finally, the teacher should provide general feedback on the class, highlighting the positive points and areas that need to be reinforced. The teacher can also take this opportunity to make a brief Introduction to the topic of the next class, arousing students' curiosity and interest.

Conclusion (5 - 7 minutes)

1. Summary of the Class (2 - 3 minutes): The teacher should start the Conclusion by making a brief summary of the main points covered in the class. This includes the definition of electrolysis, the description of the components of an electrolytic system (anode, cathode, electrolyte), the application of Faraday's laws, and the understanding of the decomposition reaction of compounds by passing electric current through them. The teacher can reinforce these concepts through direct questions to the students, ensuring knowledge retention.

2. Connection between Theory, Practice, and Applications (1 - 2 minutes): Then, the teacher should highlight how the class connected theory, practice, and applications. The teacher can mention that assembling and observing the electrolytic cell provided a practical experience of the electrolysis process, while solving problems with Faraday's laws allowed applying theoretical concepts in real situations. In addition, the teacher should reinforce the applications of electrolysis in everyday life and in the industry, recalling the examples mentioned in the Introduction of the class.

3. Complementary Materials (1 minute): The teacher should suggest some complementary materials for students who wish to deepen their understanding of the topic. These materials may include explanatory videos, interactive simulations, chemistry experiment websites, textbooks, and scientific articles. The teacher can make these materials available on the school's online learning platform or indicate where the students can find them.

4. Importance of the Subject (1 - 2 minutes): Finally, the teacher should emphasize the importance of the subject presented for everyday life and for the field of chemistry. The teacher can reinforce that electrolysis is present in several industrial processes, such as the production of metals, and that understanding this process is fundamental for the understanding of chemical and physical phenomena. In addition, the teacher can highlight that the class provided the Development of important skills, such as observation skills, problem-solving skills, and teamwork skills.