Lesson Plan | Active Learning | Organic Functions: Aromatic Hydrocarbons

Assumptions: This Active Lesson Plan assumes: a 100-minute class, prior student study with both the Book and the start of Project development, and that only one activity (among the three suggested) will be chosen to be conducted during the class, as each activity is designed to take up a significant portion of the available time.

Objectives

Duration: (5 - 10 minutes)

This stage of the lesson plan is crucial for establishing a solid foundation of understanding regarding the topic of aromatic hydrocarbons. By clearly outlining the objectives, the teacher ensures that students have a clear vision of what is expected of them by the end of the lesson. With a focus on theoretical and practical understanding, this stage paves the way for meaningful and applicable learning.

Main Objectives:

1. Empower students to understand that aromatic hydrocarbons, primarily represented by benzene, have a special molecular structure due to resonance, which influences their properties and characteristics.

2. Develop students' ability to identify and differentiate aromatic hydrocarbons from other types of hydrocarbons based on structural and behavioral characteristics.

Side Objectives:

1. Encourage students' critical analysis of the importance of aromatic hydrocarbons in the industry and in everyday applications.
2. Stimulate active participation from students in class, promoting discussion and debate about the properties of aromatic hydrocarbons.

Introduction

Duration: (15 - 20 minutes)

The introduction aims to engage students and connect the content studied at home with the practical realities and curiosities of the real world. The problem-based situations encourage students to think critically about how aromatic hydrocarbons can be applied in real-life situations, stimulating the use of prior knowledge. The contextualization, on the other hand, seeks to broaden understanding of the impact and importance of aromatic hydrocarbons, increasing students' interest in the subject.

Problem-Based Situations

1. Imagine you are a chemical engineer responsible for developing a new way to store energy. How could knowledge about the properties of aromatic hydrocarbons, such as benzene, assist in this process?

2. Consider a scenario where a perfume company wants to create a long-lasting and striking fragrance. How might the special structure of aromatic hydrocarbons influence the choice of compounds for this purpose?

Contextualization

Benzene, one of the most well-known aromatic hydrocarbons, is not only essential in the industry as a precursor to many chemical products but also has historical and even cultural relevance. Discovered by Michael Faraday in 1825, its name interestingly derives from a word used by Faraday to describe pleasant odors. Additionally, the structure of benzene was deciphered by August Kekulé in a dream of a snake biting its tail, one of the most famous examples of scientific insight in the history of chemistry.

Development

Duration: (70 - 75 minutes)

The development stage is designed for students to apply the theoretical concepts studied about aromatic hydrocarbons, particularly benzene, in a practical and creative manner. Through playful and contextualized activities, students can explore and solidify their understanding, while also developing research, decision-making, communication, and teamwork skills. The activities are designed to be engaging and challenging, stimulating students' critical thinking and curiosity.

Activity Suggestions

It is recommended to carry out only one of the suggested activities

Activity 1 - The Perfumer's Challenge

> Duration: (60 - 70 minutes)

- Objective: Apply knowledge of aromatic hydrocarbons in practice, developing research, decision-making, and communication skills.

- Description: In this activity, students will be challenged to act as perfumers in a fictional competition to create the longest-lasting and most innovative perfume. They will use their knowledge about aromatic hydrocarbons, such as benzene, to select the ingredients that will make up the perfume, considering their structures and properties to maximize aroma fixatives and pleasantness.

- Instructions:

• Divide the class into groups of up to 5 students.

• Each group receives a fictional budget to buy ingredients for their perfume, where each ingredient has an associated cost.

• Students must quickly research the properties of aromatic hydrocarbons and decide which to buy, based on characteristics such as volatility and scent fixation.

• After the purchase, groups should develop a presentation explaining their choices and how they relate to the properties of aromatic hydrocarbons.

• Conduct a vote among the groups to choose the best perfume, considering creativity, the use of chemical knowledge, and the feasibility of the choices.

Activity 2 - The Energy Factory

> Duration: (60 - 70 minutes)

- Objective: Develop engineering skills and practical application of chemical knowledge in a realistic scenario.

- Description: Students will act as engineers in a renewable energy factory that uses aromatic hydrocarbons for energy storage. They must design a storage system that maximizes energy efficiency based on the properties of benzene and other aromatic hydrocarbons.

- Instructions:

• Organize students into groups of 5.

• Provide each group with a description of the properties of aromatic hydrocarbons and their applications in energy.

• Groups must design a storage system that uses these compounds efficiently, considering factors such as cost, safety, and sustainability.

• Each group should present their project, explaining the choices made based on the chemical properties of aromatic hydrocarbons.

• Conclude with a class discussion about the different projects and their effectiveness, and how chemistry knowledge was applied in engineering.

Activity 3 - Chemical Detectives: The Benzene Mystery

> Duration: (60 - 70 minutes)

- Objective: Promote the practical application of knowledge about aromatic hydrocarbons in real situations and raise awareness about chemical safety.

- Description: In this playful activity, students will be detectives who must solve a chemical crime involving the improper use of benzene. They will use their identification and understanding skills of aromatic hydrocarbons to solve the mystery.

- Instructions:

• Divide the class into groups of up to 5 students.

• Distribute a fictional case involving improper use of benzene in a chemical products factory, resulting in health and environmental issues.

• Students must analyze samples of chemical substances and use their knowledge about benzene to identify whether the compound was used safely or not.

• Each group prepares an investigation report, highlighting how they reached their conclusions and what chemical evidence they used.

• Conduct a presentation of the reports, followed by a discussion about the risks associated with the use of benzene and the importance of its correct utilization.

Feedback

Duration: (15 - 20 minutes)

The purpose of this stage is to consolidate students' practical and theoretical learning, allowing them to reflect on the applicability of the concepts of aromatic hydrocarbons in various situations. The group discussion helps reinforce knowledge through the exchange of ideas and perspectives, as well as develop communication and argumentation skills. This moment also serves for the teacher to assess students' understanding and clarify any remaining doubts.

Group Discussion

To start the group discussion, the teacher may ask each group to briefly share their conclusions and key learnings from the activities conducted. Then, they can guide students to discuss as a larger group (all groups together) the different approaches found and how each relates to the understanding of aromatic hydrocarbons, highlighting the properties of benzene. The teacher should moderate the discussion, ensuring that all students have the opportunity to speak and that the main points are addressed.

Key Questions

1. What were the biggest challenges in applying theoretical knowledge about aromatic hydrocarbons in the practical activities?

2. How did the structural properties of aromatic hydrocarbons, especially benzene, influence the decisions made during the activities?

3. In what ways can what you learned today be applied in real situations or in other areas of knowledge?

Conclusion

Duration: (5 - 10 minutes)

The purpose of this stage is to ensure that students have consolidated the knowledge gained during the lesson, connecting theoretical points with the practical applications discussed. Furthermore, it aims to reinforce the importance of the topic studied, encouraging the perception of chemistry as a science present and active in various areas of knowledge and everyday life.

Summary

To conclude, the teacher should summarize the main points discussed about aromatic hydrocarbons, with a special focus on benzene. The structural characteristics that give these compounds their unique properties, such as resonance, should be recalled, and the practical applications studied, such as in the perfume industry and energy engineering, should be revisited.

Theory Connection

Throughout the lesson, the connection between theory and practice was clearly established through interactive activities and discussions. Students were able to apply theoretical knowledge in practical scenarios, such as creating perfumes and designing energy storage systems, which reinforced their understanding of chemical concepts and their real-world applications.

Closing

Highlighting the relevance of aromatic hydrocarbons like benzene is essential. In addition to their industrial applications, understanding these compounds helps us realize how chemistry is present in everyday life and in technological innovations, reinforcing the importance of studying chemistry for understanding and acting in the modern world.