Objectives (5 - 7 minutes)

1. Understanding the gas laws: Students should be able to understand the fundamental laws that govern the behavior of gases, particularly Boyle's Law, Charles's Law, and Gay-Lussac's Law. Additionally, they should be able to apply these laws in practical situations.

2. Calculation of molar volume: Students should be able to calculate the molar volume of a gas at standard temperature and pressure (STP). This will involve understanding the concept of mole and the application of gas laws.

3. Solving practical problems: Finally, students should be able to solve problems involving the above concepts. They should be able to apply the gas laws, the concept of mole, and the calculation of molar volume to solve real-world problems.

Secondary Objectives:

• Development of critical thinking skills: By solving problems involving complex concepts such as gas laws, students will develop their critical thinking and problems solving skills.

• Application of scientific knowledge: Students will have the opportunity to apply the scientific knowledge they have acquired in a practical and relevant context.

Introduction (10 - 15 minutes)

1. Review of previous concepts: The teacher should start the lesson by reviewing the concepts of mole and gas that were studied in previous classes. This can be done through a brief classroom discussion or a small quiz to assess students' prior knowledge.

2. Problem situation: Next, the teacher should present two problem situations to the students. The first one is: 'If you have a balloon filled with gas, what will happen if you squeeze the balloon with your hand? And if you heat the balloon with a hairdryer?' The second problem situation is: 'If you have two balloons of the same size, one filled with hydrogen and the other filled with helium, which one will be heavier? Why?' These situations will serve to arouse students' curiosity and introduce the topic in an interesting way.

3. Contextualization of the theme: The teacher should then explain the importance of studying gases and the laws that govern them. They can mention practical applications, such as the food industry (where gas laws are used to control pressure and temperature in fermentation processes) and meteorology (where gas laws are used to predict weather behavior).

4. Introduction of the topic: To introduce the topic in an engaging way, the teacher can share two fun facts about gases. The first one is that, according to the Big Bang theory, the universe began as an infinitesimal point of high density and temperature, that is, as an extremely compressed gas. The second curiosity is that the ideal gas law was formulated by a French chemist, Émile Clapeyron, in 1834, but it was only named 'ideal gas law' in his honor by another chemist, Benoît Paul Émile Clapeyron, in 1850. These curiosities should help engage students and spark their interest in the topic.

Development (20 - 25 minutes)

1. Activity 'Gas in Action' (10 - 15 minutes): This practical activity will involve the manipulation of balloons and a simple experiment to illustrate the gas laws. Students will be divided into teams of three, and each team will receive a balloon, a piece of string, and a cup of water.

   • Step 1: Each team should fill the balloon with air and measure its initial volume.

   • Step 2: Next, they should submerge the balloon in the cup of water, keeping the balloon's mouth open. They should observe what happens to the balloon.

   • Step 3: Then, they should heat the balloon with a hairdryer, keeping the balloon's mouth open. They should observe what happens to the balloon.

   • Step 4: Finally, they should squeeze the balloon with their hand and observe what happens.

   During the activity, students should record their observations and draw conclusions about the behavior of gases, relating it to the gas laws. The teacher should move around the classroom, assisting the teams and clarifying doubts.

2. Activity 'What Gas is This?' (10 - 15 minutes): In this playful activity, students will have to identify which gas is contained in different balloons, based on their observations and experiments. The teacher will prepare three balloons in advance, one containing air, another containing hydrogen, and the last one containing helium.

   • Step 1: The teacher will inflate the balloons and tie them with the string.

   • Step 2: The teams should make their assumptions about which gas is contained in each balloon, based on their previous observations and experiments.

   • Step 3: The teams will present their assumptions to the class, and the teacher will reveal which gas is in each balloon.

   This activity will help students better understand the relationship between gas laws and their behavior. Additionally, it will be an opportunity for them to apply the concept of mole and problems solving in a playful and interactive way. The teacher should encourage discussion among the teams and clarify any doubts that may arise.

3. Activity 'Real Problems' (5 - 10 minutes): To solidify students' understanding of molar volume calculation, the teacher should present real-world problems that involve the application of these concepts. The problems can be taken from textbooks or created by the teacher.

   • Step 1: The teacher should present the problem to the class and explain what is expected of them to solve it.

   • Step 2: Students, in their teams, should discuss the best way to solve the problem and present their solution to the class.

   • Step 3: The teacher should review the solution with the class and clarify any doubts that may have arisen.

   This activity will allow students to apply the acquired knowledge in a concrete and contextualized way, which will help reinforce learning. The teacher should encourage active participation from students and clarify any doubts that may arise.

Feedback (8 - 10 minutes)

1. Group Discussion (3 - 5 minutes): The teacher should gather all students and promote a group discussion about the solutions or conclusions found by each team. The goal is for students to share their observations, reflections, and problems solving strategies. During the discussion, the teacher should verify if students were able to correctly apply the gas laws, the concept of mole, and the calculation of molar volume to solve the presented problems. Additionally, the teacher should clarify any misunderstandings or doubts that may have arisen.

2. Connection with Theory (2 - 3 minutes): The teacher should then make the connection between the practical activities carried out and the theory presented at the beginning of the lesson. For example, the teacher can highlight how the experiments with the balloons illustrated the gas laws and how the activity 'What Gas is This?' helped reinforce the concept of mole. Additionally, the teacher should reinforce the importance of molar volume calculation and how it can be applied to solve real-world problems.

3. Final Reflection (3 - 5 minutes): Finally, the teacher should propose that students reflect, for a minute, on the following questions:

   • Question 1: What was the most important concept learned today?
   • Question 2: What questions have not been answered yet?

   After the reflection, the teacher should ask some students to share their answers with the class. This will help the teacher assess the effectiveness of the lesson and identify any areas that may need further clarification in future classes. Additionally, the reflection will allow students to consolidate their learning and identify any gaps in their understanding, which can be addressed in future classes or independent studies. The teacher should encourage students to be honest in their answers and not hesitate to express any doubts or difficulties they may have.

Conclusion (5 - 7 minutes)

1. Summary of Contents (2 - 3 minutes): The teacher should start the Conclusion stage by recapping the main points covered during the lesson. This includes reviewing the gas laws, introducing the concept of mole, discussing the relationship between molar volume and gases at STP, and solving practical problems involving these concepts. The teacher should do this in a way that is easy to understand and helps students consolidate what they have learned.

2. Connection between Theory, Practice, and Applications (1 - 2 minutes): Next, the teacher should highlight how the lesson managed to connect theory, practice, and real-world applications. This may include mentioning how the practical activities helped illustrate the gas laws and the concept of mole, and how real-world problems helped apply these concepts. The teacher should also reinforce the importance of these concepts in various everyday applications, such as in the food industry and meteorology.

3. Suggestion of Extra Materials (1 - 2 minutes): To complement learning, the teacher should suggest extra materials that students can refer to. This may include textbooks, educational websites, YouTube videos, among others. The teacher should emphasize the importance of students reviewing the material at home and bringing any doubts or difficulties to the next class.

4. Importance of the Subject in Everyday Life (1 minute): Finally, the teacher should emphasize the relevance of the subject to students' daily lives. They can mention again the practical applications of the learned concepts, such as the importance of gas laws in the food industry and meteorology. The teacher can also highlight how understanding these concepts can help students better comprehend the world around them.

5. End of Class (1 minute): To conclude the class, the teacher should thank the students for their participation, praise their efforts, and encourage them to continue studying the subject. They should also reinforce the importance of being prepared for the next class and bringing any doubts or difficulties they may have.