Objectives (5 - 7 minutes)

1. Understand the concept of ionic equilibrium:

   • Identify the main ions present in aqueous solutions and the importance of the equilibrium between them.
   • Distinguish between acidic, basic, and neutral solutions and understand how ionic dissociation occurs in these solutions.

2. Apply the knowledge of ionic equilibrium in practice:

   • Solve problems involving pH and pOH calculations of aqueous solutions.
   • Use equilibrium constants to determine the concentration of ions in a solution.

3. Develop critical thinking and problem-solving skills:

   • Analyze practical situations and understand how ionic equilibrium applies to them.
   • Formulate hypotheses and test them through calculations and experiments.

Secondary Objectives:

• Foster active participation of students in the class, encouraging questions and discussions.
• Promote teamwork through group activities.
• Develop communication skills by asking students to share their answers and reasoning with the class.

Introduction (10 - 15 minutes)

1. Review of Previous Content:

   • The teacher starts the lesson by reviewing the concepts of ions, ionic dissociation, pH, and pOH. These concepts are fundamental for understanding ionic equilibrium and should be well understood by the students. (3 - 5 minutes)

2. Problem Situations:

   • The teacher presents two problem situations involving ionic equilibrium. The first one could be: 'If we add an acid to a basic solution, what happens to the solution's pH?' The second one could be: 'If we have a solution of a salt and add more of this salt, what happens to the concentration of ions in the solution?' These situations serve to spark students' interest and to introduce the topic in a practical way. (3 - 5 minutes)

3. Contextualization:

   • The teacher contextualizes the importance of ionic equilibrium, explaining that it is present in various everyday situations, such as in food preparation, in maintaining blood pH, and in surface cleaning. Additionally, emphasizes that ionic equilibrium is fundamental for understanding other topics in chemistry, such as chemical kinetics and electrochemistry. (2 - 3 minutes)

4. Topic Introduction:

   • The teacher introduces the topic of ionic equilibrium in an engaging way, telling an anecdote or story related to the subject. For example, they can tell the story of how understanding ionic equilibrium was crucial for the development of modern medicine, allowing the development of more effective and safe medications. Or they can mention the curiosity that the color of many foods and flowers is determined by ionic equilibrium. (2 - 3 minutes)

Development (20 - 25 minutes)

1. Modeling Activity: 'The Ion War' (10 - 12 minutes)

   • The teacher divides the class into groups of up to 5 students.
   • Each group receives a set of cards, each representing a different ion (for example, H+, OH-, Na+, Cl-). Additionally, each group receives a container representing an aqueous solution.
   • The goal of the game is to form the solution with the highest possible pH by adding or removing ions. The groups have to strategically decide which ions to add and which to remove, remembering that pH is a measure of the concentration of H+ ions in the solution.
   • During the game, the teacher circulates around the room, observing the groups' work and clarifying doubts.
   • After a set time, the teacher interrupts the game and asks each group to explain the strategy they used. This allows students to apply the concept of ionic equilibrium in practice and develop their critical thinking skills.

2. Practical Activity: 'The pH in Real Life' (10 - 12 minutes)

   • The teacher presents students with a series of everyday scenarios involving ionic equilibrium. For example, they may ask: 'What happens to the pH of lemon juice when we add sugar?', 'Why is the pH of rainwater lower than the pH of distilled water?', 'How is the pH of blood kept constant?'
   • Each group chooses one of the scenarios and, using the knowledge acquired in the lesson, tries to explain the phenomenon in terms of ionic equilibrium. They can do quick research on the internet if necessary.
   • After a set time, each group presents their conclusions to the class. The teacher should encourage discussion and ask questions to deepen students' understanding.

3. Research Activity: 'Ionic Equilibrium in Nature' (5 - 7 minutes)

   • The teacher asks students to individually research and note examples of how ionic equilibrium is important for nature.
   • After the research, students share their findings with the class. This allows them to see the relevance of what they are learning and how chemistry is present in their daily lives.

These activities are designed to promote active learning, collaboration among students, and practical application of knowledge. Additionally, they are fun and engaging, which helps maintain students' attention.

Return (10 - 15 minutes)

1. Group Discussion (5 - 7 minutes):

   • The teacher gathers all students and initiates a group discussion about the solutions or conclusions found by each team during the modeling and practical activities.
   • Each group has up to 3 minutes to share their strategies, conclusions, and learnings with the class. During the presentations, the teacher should encourage students to ask questions and make comments, thus promoting interaction and exchange of ideas among students.
   • The teacher makes connections between the solutions proposed by the groups and the theory presented in the lesson, reinforcing concepts and clarifying possible misconceptions.

2. Learning Verification (3 - 5 minutes):

   • The teacher then proposes a learning verification activity. It can be a short quiz, a challenge to solve a problem related to ionic equilibrium, or a question for group discussion.
   • The goal is to assess how well students have understood the subject, identify possible knowledge gaps, and reinforce the most important concepts.
   • The teacher collects students' answers, either orally or in writing, and provides immediate feedback, correcting possible errors and reinforcing correct answers.

3. Final Reflection (2 - 3 minutes):

   • To conclude the lesson, the teacher suggests that students reflect on what they have learned.
   • The teacher presents some questions to guide the reflection, such as: 'What was the most important concept you learned today?' and 'What questions have not been answered yet?'
   • Students have a minute to think about their answers and then are invited to share them with the class.
   • The teacher should listen attentively to students' responses, valuing their contributions and clarifying any remaining doubts.

This Return moment is essential to consolidate learning, check students' understanding, and identify possible difficulties. Furthermore, by promoting reflection and discussion, the teacher stimulates critical thinking and students' autonomy, essential skills for meaningful learning.

Conclusion (5 - 7 minutes)

1. Recap of Contents (2 - 3 minutes):

   • The teacher summarizes the main points covered during the lesson, recalling the concept of ionic equilibrium, ionic dissociation, the importance of pH and pOH, and how to calculate these quantities in aqueous solutions.
   • The teacher should make connections between the theory presented and the practical activities, highlighting how the concepts were applied and understood by the students.

2. Connection between Theory and Practice (1 - 2 minutes):

   • The teacher emphasizes how the practical and modeling activities helped illustrate and deepen the presented theory.
   • They highlight that the goal of these activities was to allow students not only to understand the concepts but also to apply them in real situations, developing their critical thinking and problem-solving skills.

3. Suggestion of Additional Materials (1 - 2 minutes):

   • The teacher suggests some additional materials for students who wish to deepen their knowledge of ionic equilibrium.
   • These materials may include chemistry books, educational videos, research institution websites, and simple experiments that can be done at home.
   • The teacher should emphasize that autonomous study is an important part of the learning process and that exploring these materials can help students consolidate and expand their knowledge.

4. Importance of Ionic Equilibrium in Daily Life (1 minute):

   • Finally, the teacher reinforces the importance of ionic equilibrium for daily life, reminding that it is present in various situations, from food preparation to maintaining blood pH.
   • The teacher highlights that by understanding and applying the concept of ionic equilibrium, students not only acquire valuable knowledge in chemistry but also develop a deeper understanding of the world around them.

The Conclusion is an essential moment to consolidate learning, reinforce the relevance of what was learned, and encourage further studies. By providing an overview of the contents, making connections with practice, and suggesting additional materials, the teacher helps students internalize knowledge and become more autonomous and motivated learners.