Objectives (5 - 7 minutes)

1. Understand the structure and nomenclature of esters:

   • Identify the chemical structure of esters and understand how it differs from other organic functions.
   • Learn the nomenclature of esters, including common names and the IUPAC system.

2. Apply knowledge about esters in everyday life:

   • Recognize esters in daily use products, such as food, perfumes, and medications.
   • Understand the importance of esters in industry and everyday life.

3. Solve application exercises on the topic:

   • Perform calculations of molar mass and percentage of elements in ester compounds.
   • Solve problems of nomenclature and identification of ester structures in exercises.

Secondary Objectives:

• Stimulate students' critical thinking and curiosity about the world of chemistry and its applications.
• Promote interaction among students through discussions and problem-solving in groups.

Introduction (10 - 15 minutes)

1. Review of necessary contents:

   • The teacher should start the lesson by reviewing the concepts of organic functions, such as aldehydes, ketones, carboxylic acids, and alcohols, as understanding these topics is fundamental to the comprehension of esters.
   • Also, review the IUPAC nomenclature rules, as they will be applied in the nomenclature of esters.

2. Problem situations:

   • The teacher can present two situations that arouse students' curiosity about the topic. For example:
     • "Have you ever wondered why certain foods and fruits have such pleasant smells? And why do some beauty products, like shampoos and conditioners, also have these scents?"
     • "What if I told you that the formation of esters is a fundamental process in the production of many plastics and resins we use in our daily lives, would you believe it?"

3. Contextualization:

   • The teacher should explain that esters are widely used in the food, perfume, medication industry, and even in the production of sustainable bioplastics.
   • They can mention examples of esters found in everyday products, such as methyl ethanoate (banana essence), ethyl ethanoate (pineapple essence), and ethyl butanoate (strawberry essence).
   • The teacher can also mention that the formation of esters is an important process in flavor chemistry, contributing to the aroma and taste of many foods and beverages.

4. Introduction to the topic:

   • The teacher should introduce the topic of esters by explaining that they are organic compounds with a characteristic structure that gives them unique properties, such as a pleasant and sweet smell.
   • They can show the general formula of an ester and highlight the differences between the structure of an ester and that of other organic compounds, such as alcohols and carboxylic acids.
   • To capture students' attention, the teacher can share curiosities, such as the fact that the simplest ester, methyl methanoate, is the main component of the smell of green apples and the smell of some flowers.
   • Another interesting curiosity is that esters are responsible for the characteristic smell of many cleaning solvents and nail polish removers.

Development (20 - 25 minutes)

1. Activity "Discovering Ester in Nature":

   • Description: The teacher divides the class into small groups and provides each of them with a list of fruits, flowers, or other natural products (such as vinegar or wine) that contain esters in their composition. The goal of the activity is for students to identify which esters are present in each item and describe their characteristics, such as odor and taste.
   • Step by step:
     1. The teacher distributes the lists of natural products to each group.
     2. The students, in their groups, research the esters present in the items on their lists, using textbooks or online resources.
     3. Each group presents their findings to the class, explaining the structure of the ester, its characteristics, and how it contributes to the odor or taste of the product.
     4. The teacher makes the connection between the activity and the theory, reinforcing the importance of esters in everyday life and industry.

2. Activity "Create Your Own Ester":

   • Description: In this activity, students will have the opportunity to create their own ester. They will combine a carboxylic acid (which can be found in foods like vinegar and lemon juice) with an alcohol (such as ethanol, which can be found in alcoholic beverages). The result will be an ester with a characteristic aroma.
   • Step by step:
     1. The teacher organizes the class into groups and provides each group with a small glass flask, carboxylic acid (for example, vinegar), and an alcohol (for example, ethanol).
     2. The students, in their groups, carefully measure an equal amount of carboxylic acid and alcohol and mix the two in the flask.
     3. They close the flask with a cork and gently shake to mix.
     4. The students observe and describe the changes that occur in the mixture over time. They also record the smell of the mixture before and after the reaction.
     5. The teacher makes the connection between the activity and the theory, explaining that the reaction they observed is the formation of an ester. They also highlight that this is the same process that occurs in the industry to create many of the scents we find in our daily products.

3. Activity "Identifying Esters in Everyday Products":

   • Description: In this activity, students will apply their knowledge about esters to identify them in everyday use products. The teacher brings a variety of products, such as fruits, perfumes, medications, and asks students to identify if they contain esters and, if so, which esters are present.
   • Step by step:
     1. The teacher brings a variety of products and places them at different workstations.
     2. The students, in their groups, visit each station and perform tests to determine if the product contains esters. They can use a diluted sodium hydroxide solution to test for the presence of an ester.
     3. If the test is positive, students should try to identify the ester present in the product, based on their knowledge of esters and their characteristics.
     4. Students record their findings and share them with the class. The teacher provides feedback and guidance as needed.
   • Note: It is important to ensure that students are safe and follow all safety precautions when conducting tests and handling chemicals. The teacher should closely supervise the activities and provide guidance as needed.

After these activities, the teacher should hold a classroom discussion to clarify any doubts and reinforce the concepts learned. This is an opportunity for students to actively engage in learning, applying theory in practice, and developing problem-solving and critical thinking skills.

Return (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. Each group should briefly present the solutions they found for the activities carried out.
   • During the presentation, the teacher should encourage other groups to ask questions and make comments, thus promoting interaction and knowledge sharing among students.
   • The teacher should take the opportunity to reinforce the concepts learned, correct possible errors, and clarify any remaining doubts.

2. Connection with Theory (2 - 3 minutes):

   • After the presentations, the teacher should make the connection between the activities carried out and the theory discussed in the Introduction of the lesson.
   • For example, it can be highlighted how the activity "Discovering Ester in Nature" illustrates the presence of esters in everyday products, how the formation of esters was demonstrated in the activity "Create Your Own Ester", and how the activity "Identifying Esters in Everyday Products" allowed students to apply their knowledge of ester nomenclature and structure.
   • The teacher can also reinforce the importance of esters in industry and everyday life, citing examples of products containing esters, such as food, perfumes, medications, and plastics.

3. Individual Reflection (1 - 2 minutes):

   • To conclude the lesson, the teacher should propose that students reflect individually for a minute on what they have learned.
   • 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?".
   • The goal of this reflection is for students to internalize the acquired knowledge, identify any gaps in their understanding, and prepare for future lessons or studies on the topic.

4. Feedback and Closure (1 minute):

   • The teacher should end the lesson by thanking the students for their participation and providing brief feedback on the class performance.
   • The teacher can also take this opportunity to announce the theme of the next lesson and remind students of any tasks or readings that need to be completed before the next class.

This Return is a crucial stage of the lesson, as it allows the teacher to assess students' understanding of the topic, correct any misunderstandings, and prepare students for future lessons or studies. Additionally, it promotes reflection and active learning among students, which can increase knowledge retention and application.

Conclusion (5 - 7 minutes)

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

   • The teacher should recap the main points covered during the lesson, reinforcing the structure and nomenclature of esters.
   • They should also remind students of the practical activities carried out, emphasizing the discoveries made and the conclusions drawn.
   • Additionally, the teacher should recall the importance of esters in everyday life and industries, exemplifying with the products mentioned during the lesson.

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

   • The teacher should explain how the lesson connected the theory, practice, and applications of esters.
   • They should emphasize how the practical activities allowed students to apply the theoretical concepts learned and better understand the applications of esters.
   • They should also explain how the classroom discussion deepened students' understanding and encouraged critical thinking and curiosity.

3. Extra Materials (1 minute):

   • The teacher can suggest extra materials for students who wish to deepen their knowledge on the topic.
   • These materials may include books, articles, videos, chemistry websites, and online activities.
   • The teacher should emphasize that these materials are optional and are intended for students who want to explore more about the subject.

4. Importance of the Subject (1 minute):

   • To conclude, the teacher should reinforce the importance of the topic addressed for students' daily lives.
   • They can emphasize that by understanding the structure and properties of esters, students can better appreciate the smells and tastes of foods, understand the ingredients of beauty and cleaning products, and comprehend the role of esters in the plastics and resins industry.

The Conclusion is a vital part of the lesson, as it helps consolidate the acquired knowledge and motivates students to continue learning about the subject. Additionally, by emphasizing the relevance and applications of the topic, the teacher can increase students' interest and motivation for studying chemistry.