Objectives (5 - 10 minutes)

1. Understand the concept of ester and its importance in organic chemistry.

   • Students should be able to define the ester as an organic function, identifying its structural and functional characteristics.
   • They should understand the nomenclature and classification of esters, recognizing the different organic radicals present in their structure.

2. Identify the presence of esters in everyday life and in various industrial applications.

   • Students should be able to identify common products containing esters, such as perfumes, soaps, vegetable oils, among others.
   • They should understand the relevance of esters in the food, pharmaceutical, and cosmetic industries.

3. Perform the nomenclature and writing of structural formulas of esters.

   • Students should practice the systematic and trivial nomenclature of esters, as well as the writing of the structural formulas of these compounds.
   • They should be able to identify the organic radicals present in the ester structure and correctly name each of them.

Secondary Objectives:

• Develop research and autonomous study skills, encouraging students to find examples of esters in their daily lives.
• Promote debate in the classroom about the importance of esters in everyday life and in the industry, stimulating critical reflection on the role of chemistry in society.

Introduction (10 - 15 minutes)

1. Review of concepts:

   • The teacher should start the lesson by briefly reviewing the organic functions concepts already studied, such as aldehydes, ketones, carboxylic acids, and alcohols. This review is essential for students to make the necessary connections and understand the structure of the ester. (5 minutes)

2. Problem situations:

   • The teacher can present two problem situations to arouse students' interest. The first one could be the question of why perfumes have such an intense and long-lasting scent, and the second one could be why vegetable oils are so effective in lubricating machines and gears. Both situations have in common the presence of esters, which will be the focus of the lesson. (5 minutes)

3. Contextualization:

   • The teacher should then contextualize the importance of esters, explaining that they are present in our daily lives in various ways. In addition to the examples mentioned, esters are also used in the manufacture of plastics, solvents, dyes, and soaps. Therefore, the study of esters has practical and relevant applications in society. (2 minutes)

4. Introduction to the topic:

   • To introduce the topic in an engaging way, the teacher can share curiosities about esters. For example, he can mention that the word 'ester' comes from the Latin 'aes meaning' wine of must and 'oleum' meaning oil, due to its presence in wines and vegetable oils. Furthermore, the teacher can mention that the production of esters is an ancient chemical reaction, which was used in the manufacture of perfumes and fragrances long before the nature of chemical reactions was understood. (3 minutes)

Development (20 - 25 minutes)

1. Theory about esters (10 - 12 minutes)

   • The teacher should start by explaining that esters are organic compounds whose molecules have the ester function, characterized by the presence of an acyl group (RCO-) linked to an oxygen atom, which in turn is linked to a carbon atom. This explanation should be accompanied by a graphical representation of the ester's structure.
   • Next, the teacher should detail the two components of the ester's structure: the acyl group (RCO-), which originates from a carboxylic acid by the loss of a hydrogen from the carboxyl, and the oxygen, which is linked to the carbon of the acyl group and to a second carbon.
   • The teacher should then clarify that the carbon linked to oxygen is called gamma carbon (γ) and the carbon of the acyl group is called alpha carbon (α). It is important to emphasize that the ester is a primary ester if the α carbon is linked only to a carbon atom and a hydrogen atom (or an alkyl substituent radical). If the α carbon is linked to two carbon atoms, the ester is secondary, and if the α carbon is linked to three carbon atoms, the ester is tertiary.
   • Finally, the teacher should explain that the nomenclature of esters follows the general rule of organic functions, that is, the acyl group is named as a carboxylic acid, but with the ending -oate. For example, the ester formed from formic acid (or methanoic acid) is called methyl formate. If the ester is formed from a dicarboxylic acid, the nomenclature changes slightly, but the -oate ending is still used.

2. Examples of esters in everyday life and in the industry (5 - 7 minutes)

   • The teacher should present a list of common products containing esters, such as perfumes, soaps, vegetable oils, dyes, among others. For each product, the teacher should explain how esters contribute to their properties and uses.
   • The teacher should also discuss the importance of esters in the industry, mentioning that they are used in the manufacture of plastics (such as PET), solvents (such as ethyl acetate), dyes (such as aniline dyes), and soaps (such as coconut soap). Additionally, the teacher should emphasize that esters are used in biological processes, such as the synthesis and degradation of fats and oils.

3. Practice of nomenclature and writing of structural formulas of esters (5 - 6 minutes)

   • The teacher should propose some exercises of nomenclature and writing of structural formulas of esters, aiming to reinforce the theoretical content presented. The exercises can be solved collectively, with active participation of the students. The teacher should take advantage of this practice to clarify possible doubts and correct misunderstandings.
   • The teacher should also emphasize the importance of precision and clarity in the nomenclature and writing of structural formulas, as errors in this process can lead to misinterpretations and consequent errors in chemical reactions.

Return (10 - 15 minutes)

1. Review of concepts (5 - 7 minutes):

   • The teacher should start this stage by asking students what were the most important concepts they learned during the lesson. This will allow the teacher to assess the level of understanding of the students and clarify any remaining doubts.
   • Next, the teacher should briefly review the main concepts of the lesson, reinforcing the structure and function of esters, the importance of esters in everyday life and in the industry, and the nomenclature and writing of structural formulas of esters.
   • The teacher should also make connections between theoretical concepts and practical applications, using examples from everyday life and the industry to illustrate and reinforce the concepts. For example, the teacher can ask students how the structure of esters contributes to their physical and chemical properties, and how this is reflected in their applications in everyday life and in the industry.

2. Reflection on learning (3 - 5 minutes):

   • The teacher should propose to students to reflect for a minute on the following questions: 'What was the most important concept you learned today?' and 'What questions have not been answered yet?'. Students should write down their answers on a piece of paper.
   • Then, the teacher should ask some students to share their answers with the class. This will allow the teacher to assess the level of understanding of the students and identify any gaps in learning that need to be addressed in future classes.
   • The teacher should encourage students to express their doubts and opinions, creating an open and collaborative learning environment. The teacher should value all contributions from students and should not criticize or devalue wrong answers.

3. Connection with the real world (2 - 3 minutes):

   • Finally, the teacher should explain to students how what they learned in the lesson connects with the real world. For example, the teacher can mention that the ability to identify and name esters is a useful skill for those working in industries that use these compounds, such as the perfume, cosmetics, food, plastics, and solvents industries.
   • The teacher should also emphasize that knowledge about esters can be applied in many other areas of chemistry and other sciences, such as biochemistry, pharmacology, materials engineering, and food science. This can help motivate students to learn and apply chemistry concepts in their daily lives and future careers.

Conclusion (5 - 7 minutes)

1. Recapitulation of contents (2 - 3 minutes):

   • The teacher should start the Conclusion by recalling the main concepts covered in the lesson, such as the definition and structure of esters, the importance of esters in everyday life and in the industry, and the nomenclature and writing of structural formulas of esters.
   • The teacher should emphasize the relevance of these contents, explaining that they are fundamental for the understanding of organic chemistry and for the application of chemistry in various areas of everyday life and industry.

2. Connection between theory, practice, and applications (1 - 2 minutes):

   • The teacher should then make the connection between the presented theory, the performed practice, and the discussed applications.
   • He should explain how understanding the structure of esters and the nomenclature of esters allows the correct identification and description of these compounds, which is essential for the application of chemistry in various areas, such as the perfume, cosmetics, food, plastics, and solvents industries.

3. Suggestion of extra materials (1 - 2 minutes):

   • The teacher should suggest some extra materials for students who wish to deepen their knowledge about esters. These materials may include chemistry books, chemistry websites, educational videos, and simple experiments that illustrate the properties and reactions of esters.
   • The teacher should encourage students to explore these materials in their own time, and to bring their doubts and discoveries to the next class.

4. Importance of the topic for daily life (1 minute):

   • Finally, the teacher should summarize the importance of the lesson's topic for students' daily lives.
   • He should reinforce that esters are present in many products we use daily, and that knowledge about these compounds can help us better understand these products and make more conscious choices.
   • Additionally, the teacher should highlight that the ability to identify and name esters is a useful skill in many careers, especially in the fields of chemistry, pharmacy, materials engineering, and food science.