Objectives (5 - 7 minutes)

1. Understand the concept of vapor pressure and its application in colligative properties: Students should be able to understand vapor pressure as the pressure exerted by a gas in equilibrium with its liquid or solid in a closed container. They should also learn to apply this concept in solving problems related to colligative properties.

2. Apply Raoult's law to calculate the vapor pressure of an ideal solution: Students should be able to apply Raoult's law, which describes the vapor pressure of a component in an ideal solution, to calculate the vapor pressure of a solution.

3. Solve problems involving the vapor pressure of an ideal solution: Students should be able to solve problems involving the calculation of the vapor pressure of an ideal solution, using Raoult's law.

Secondary Objectives:

• Relate vapor pressure to temperature: Students should understand that the vapor pressure of a substance increases with temperature and decreases with decreasing temperature.

• Recognize the importance of vapor pressure: Students should be able to recognize the importance of vapor pressure in everyday phenomena, such as the evaporation of liquids and the cooking of food.

Introduction (10 - 15 minutes)

1. Review of previous content: The teacher should start the lesson by reviewing the concepts of solutions, solvent, and solute, as well as the colligative properties already studied (elevation and lowering of the boiling point, and elevation and lowering of the melting point). It is important for students to have these concepts well consolidated in order to advance in the study of vapor pressure.

2. Problem situations: The teacher can propose two problem situations to arouse students' interest and contextualize the theme of the lesson:

   • Situation 1: "Why does water take longer to boil at high altitudes, such as at the top of a mountain?"
   • Situation 2: "Why does a liquid, like water or alcohol, evaporate more quickly when left in an open container?"

3. Contextualization: The teacher should then explain that vapor pressure is directly related to these situations: in situation 1, the atmospheric pressure is lower at high altitudes, resulting in a lower vapor pressure of water and, consequently, a lower boiling point. In situation 2, rapid evaporation is due to a high vapor pressure of these liquids.

4. Presentation of the topic: The teacher should introduce the topic of vapor pressure, explaining that it is the pressure exerted by a gas in equilibrium with its liquid or solid in a closed container. He can highlight the importance of this concept in Chemistry and in everyday phenomena, such as the evaporation of liquids and the cooking of food.

5. Curiosities: To arouse students' curiosity, the teacher can share some curiosities:

   • Curiosity 1: "Did you know that the boiling point of water is higher in a pressure cooker than in a normal pot? This is because the pressure cooker increases the pressure on the water, which raises its boiling point."
   • Curiosity 2: "Did you know that vapor pressure is one of the factors that determines the aroma of coffee? This is because, when water is heated during the coffee preparation process, the aromatic compounds present in the coffee vaporize more easily due to the increased vapor pressure."

Development (20 - 25 minutes)

1. Theory - Concept of Vapor Pressure (5 - 7 minutes): The teacher should start the theoretical part by explaining the concept of vapor pressure. He should emphasize that vapor pressure is the pressure exerted by a gas in equilibrium with its liquid or solid in a closed container. The teacher can use a particle model to illustrate the concept, showing how the gas particles are constantly colliding with the surface of the liquid or solid and, therefore, exerting pressure. He should also emphasize that vapor pressure increases with temperature and decreases with decreasing temperature.

2. Theory - Raoult's Law (5 - 7 minutes): Next, the teacher should introduce Raoult's law. He should explain that Raoult's law describes the vapor pressure of a component in an ideal solution and that, according to this law, the vapor pressure of a component in a solution is equal to the vapor pressure of that pure component multiplied by the component's molar fraction in the solution. The teacher can make a mathematical demonstration of Raoult's law, showing how to apply this formula to calculate the vapor pressure of a component in a solution.

3. Practice - Examples of Applying Raoult's Law (5 - 7 minutes): After the theoretical explanation, the teacher should present some examples of applying Raoult's law. He should show how to calculate the vapor pressure of a component in a solution, given the vapor pressure of that pure component and the molar fraction of the component in the solution. The teacher should solve these examples step by step, explaining each stage of the process.

4. Practice - Problem Solving (5 - 7 minutes): Finally, the teacher should propose some problems for the students to solve. The problems should involve calculating the vapor pressure of a component in a solution, using Raoult's law. The teacher should guide the students in solving these problems, providing tips and clarifying doubts. He should also explain the importance of checking the units and rounding the answers correctly.

5. Discussion - Importance of Vapor Pressure (3 - 5 minutes): After the practice, the teacher should promote a discussion about the importance of vapor pressure. He should remind students that vapor pressure is directly related to the boiling point and evaporation of a liquid. The teacher can also ask students to think of other examples of phenomena influenced by vapor pressure, such as cooking food and drying clothes. He should emphasize that understanding vapor pressure is essential not only in Chemistry but also to understand these everyday phenomena.

Return (8 - 10 minutes)

1. Review of concepts (3 - 4 minutes): The teacher should start the Return phase by asking students to summarize what they learned in the lesson. He can ask questions like "What is vapor pressure?" "What is Raoult's law?" and "How do you calculate the vapor pressure of a component in a solution using Raoult's law?" This helps to verify if students understood the main concepts of the lesson.

2. Connection to the real world (3 - 4 minutes): Next, the teacher should ask students to relate what they learned to everyday situations. For example, he can ask, "How does vapor pressure affect the boiling point of water?" or "Why does a liquid evaporate more quickly when left in an open container?" This helps to consolidate learning, showing students that the concepts studied have practical application and relevance in their lives.

3. Reflection on learning (2 - 3 minutes): Finally, the teacher should propose that students reflect for a moment on what they have learned. He can ask questions like "What was the most important concept learned today?" and "What questions have not been answered yet?" The teacher should encourage students to express their reflections, either orally or in writing. This helps to solidify learning and identify possible gaps in understanding that can be addressed in future classes.

4. Teacher's feedback (1 minute): The teacher should then provide feedback to students, highlighting the positives and areas for improvement. He should praise students' efforts, acknowledging what was well done, and offer guidance for future improvements, if necessary. The teacher should also reinforce the importance of the topic studied and the need to practice the concepts learned to consolidate understanding.

5. End of the lesson (1 minute): Finally, the teacher should end the lesson by emphasizing the importance of the subject studied and giving a brief Introduction to the topic of the next lesson. He can also remind students of any tasks or readings that need to be done to prepare for the next class.

Conclusion (5 - 7 minutes)

1. Summary of key contents (2 - 3 minutes): The teacher should recap the main concepts covered during the lesson. He should reinforce the concept of vapor pressure, Raoult's law, and how to calculate the vapor pressure of a component in an ideal solution. The teacher can briefly review the examples and problems solved during the lesson to help students consolidate what they have learned.

2. Connection between theory, practice, and applications (1 - 2 minutes): Next, the teacher should emphasize how the lesson connected theory, practice, and applications. He can highlight how the theory of vapor pressure and Raoult's law were applied in solving problems and how these concepts relate to everyday phenomena, such as the boiling point of water at different altitudes and the evaporation of liquids.

3. Extra materials (1 - 2 minutes): The teacher should then suggest some extra materials for students who wish to deepen their knowledge on the topic. These materials may include textbooks, educational videos, Chemistry websites, and review exercises. The teacher can also recommend that students practice more problem-solving involving vapor pressure to further consolidate what they have learned.

4. Importance of the subject (1 minute): Finally, the teacher should emphasize the importance of the subject studied. He can explain that vapor pressure is a fundamental concept in Chemistry, involved in a variety of processes, from the evaporation of liquids to the cooking of food. The teacher should also emphasize that understanding vapor pressure and colligative properties is essential for solving many practical problems and for success in future Chemistry studies.

5. End (1 minute): To conclude, the teacher should thank the students for their participation, reinforce the importance of continuous study, and encourage them to bring any questions they may have to the next lesson.