Objectives (5 - 7 minutes)

1. Understand the concept of solution, mixture, and chemical reaction, and how they relate.

2. Identify the characteristics and properties of solutions, mixtures, and chemical reactions.

3. Apply the acquired knowledge to solve practical problems involving the formation of solutions through mixtures that involve chemical reactions.

Secondary Objectives:

1. Develop critical thinking and problem-solving skills by applying theoretical knowledge in practice.

2. Foster teamwork, effective communication, and collaboration among students through practical group activities.

Introduction (10 - 15 minutes)

1. Review of Previous Content:

   • The teacher starts the lesson by reviewing basic concepts of mixtures and chemical reactions. They can use simple examples, such as the dissolution of salt in water (a mixture) and the combustion of a matchstick (a chemical reaction).
   • It is also important to review the definition of solute and solvent, and how they behave in a solution.

2. Problem Situations:

   • The teacher proposes two problem situations:
     1. Imagine you have a solution of hydrochloric acid (HCl) and you add a piece of zinc (Zn) to it. What happens? Why?
     2. You have a solution of copper sulfate (CuSO4) and a solution of sodium hydroxide (NaOH). What happens when you mix the two solutions? Why?

3. Contextualization:

   • The teacher highlights the importance of studying solutions, mixtures, and chemical reactions, relating them to everyday situations. For example, how meal preparation can involve the formation of solutions through mixtures that involve chemical reactions, such as cooking food.

4. Engaging Students' Attention:

   • The teacher can share two curiosities to grab students' attention:
     1. The first one is about the famous 'disappearing elephant,' an experiment in which a piece of zinc is added to a solution of hydrochloric acid and a piece of copper. The zinc 'disappears' while the copper remains unchanged. The teacher can ask students why this happens and discuss the reaction taking place.
     2. The second curiosity is about the formation of a solution of copper sulfate (CuSO4) and sodium hydroxide (NaOH), which produces a blue precipitate. The teacher can ask students why this happens and discuss the chemical reaction taking place.

Development (20 - 25 minutes)

1. Practical Activity: 'Magic Solution' (10 - 15 minutes)

   • Required Materials: A transparent glass, water, a packet of powdered drink mix (preferably sugar-free and in a different color from the reagent packet), a teaspoon of baking soda, a packet of chemical reagent (e.g., pH indicator paper packet).
   • Procedure:
     1. The teacher divides the class into groups of up to five students and distributes the materials.
     2. Each group should add water to the glass (solvent) and then mix the drink powder (solute) into the water, forming a colored solution.
     3. Next, they should add the baking soda (reagent) to the solution and observe what happens. (The solution should change color.)
     4. Finally, they add the chemical reagent packet and observe another change in the solution's color.
   • Objective: This activity aims to illustrate the concept of solution and mixture with a chemical reaction in a playful and practical way, allowing students to observe the changes that occur when different substances are mixed.

2. Discussion and Analysis Activity: 'Solutions and Mixtures in the Kitchen' (10 - 15 minutes)

   • Required Materials: Images of common cooking ingredients (e.g., salt, sugar, yeast, vinegar, etc.), a list of questions prepared by the teacher.
   • Procedure:
     1. The teacher shows the images of the ingredients and asks students if they are solutes or solvents.
     2. Then, the teacher asks questions related to the formation of solutions and mixtures in the kitchen. For example, 'What happens when you add salt to boiling water to cook pasta?' or 'Why does yeast make the cake batter rise?'.
     3. Students should discuss in groups and present their answers. The teacher should provide feedback and guidance as needed.
   • Objective: This activity aims to reinforce students' understanding of solutions and mixtures, and how these concepts apply to everyday situations, such as in the kitchen.

3. Virtual Laboratory Activity: 'Chemical Reactions in Solutions' (5 - 10 minutes)

   • Required Materials: Virtual laboratory simulator (e.g., the PhET Interactive Simulations from the University of Colorado), instructions for use, and guiding questions prepared by the teacher.
   • Procedure:
     1. The teacher explains to students how to use the virtual laboratory simulator and presents the instructions for the activity.
     2. Students, still in their groups, should conduct virtual experiments in the simulator, following the teacher's instructions and answering the guiding questions.
   • Objective: This activity aims to allow students to explore chemical reactions in solutions safely and interactively, applying the acquired knowledge in a practical and visually appealing way.

Feedback (10 - 12 minutes)

1. Group Discussion (5 - 7 minutes)

   • The teacher gathers the class and asks each group to share the solutions or conclusions they reached during the activities.
   • Each group has a maximum of 3 minutes to present. During the presentations, the teacher should encourage students to explain their reasoning and justify their answers, promoting the exchange of ideas and debate.
   • The teacher should ask questions to ensure that all important concepts were understood and to correct any misunderstandings.

2. Connection to Theory (2 - 3 minutes)

   • After all presentations, the teacher should review the theoretical concepts that were applied during the activities.
   • The teacher can highlight how the practical activities illustrate and reinforce the theory, and how theoretical concepts are applied in real-world situations.
   • This is an opportunity for the teacher to clarify any remaining doubts and for students to consolidate their understanding of the content.

3. Individual Reflection (2 - 3 minutes)

   • The teacher suggests that students silently reflect on what they learned during the lesson.
   • The teacher can ask guiding questions, such as: 'What was the most important concept you learned today?' and 'What questions have not been answered yet?'.
   • Students should write down their answers, which can be shared with the class or handed to the teacher, if they prefer.
   • This reflection step is crucial to ensure that students are aware of what they learned and to identify any areas that still need reinforcement or clarification.

4. Feedback and Closure (1 minute)

   • The teacher thanks everyone for their participation and asks students to provide feedback on the lesson.
   • The teacher can ask: 'What did you like about today's lesson?' and 'What could be improved?'.
   • Students' feedback is valuable for the teacher to assess the effectiveness of the lesson and make adjustments, if necessary, for future classes.
   • The teacher concludes the lesson by reinforcing key concepts and highlighting the importance of studying solutions, mixtures, and chemical reactions.

Conclusion (5 - 7 minutes)

1. Summary and Recap (2 - 3 minutes)

   • The teacher summarizes the main points covered during the lesson, reinforcing the definition of solution, mixture, and chemical reaction, and how they relate.
   • They remind students about the characteristics and properties of solutions, mixtures, and chemical reactions, and how they can be identified and observed.
   • The teacher also recaps the practical activities carried out, highlighting the theoretical concepts that were applied and reinforced through them.

2. Connecting Theory with Practice (1 - 2 minutes)

   • The teacher emphasizes how the lesson connected theory and practice, demonstrating how the discussed theoretical concepts were applied and observed in the practical activities.
   • They reinforce that theoretical understanding is essential for practical application and that the acquired knowledge will enable students to understand and explain everyday phenomena involving solutions, mixtures, and chemical reactions.

3. Extra Materials (1 minute)

   • The teacher suggests additional materials for students who wish to deepen their knowledge on the subject. This may include recommended readings, explanatory videos, interactive websites, and additional exercises.
   • For example, they may recommend a video of a fun and educational experiment illustrating the formation of solutions through mixtures involving chemical reactions.
   • The teacher may also suggest an interactive website where students can conduct virtual experiments to explore more about chemical reactions in solutions.

4. Application in Everyday Life (1 minute)

   • Finally, the teacher emphasizes the relevance of the learned content for students' daily lives. For example, they may mention how knowledge about solutions, mixtures, and chemical reactions can be useful in everyday situations, such as meal preparation, house cleaning, or even in understanding industrial processes.
   • The teacher concludes the lesson by encouraging students to observe the world around them with a more chemical perspective, recognizing the numerous applications and implications of solutions, mixtures, and chemical reactions.