Lesson Plan | Active Learning | Oxidation Number

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)

The Objectives phase is crucial for clearly defining what students should achieve by the end of the lesson. This initial phase guides both students and the teacher regarding the learning goals, helping to maintain focus during practical activities and discussions in class. Thus, students can direct their efforts towards understanding and effectively applying the concepts of oxidation number.

Main Objectives:

1. Ensure that students understand the concept of oxidation number (NOX) as a measure of the oxidation state of an atom in a substance.

2. Enable students to calculate the oxidation number in different chemical compounds using the rules of oxidation.

Introduction

Duration: (15 - 20 minutes)

The Introduction phase is designed to engage students and connect prior knowledge with the content of the lesson. Problem situations stimulate students to think critically about how to apply the oxidation number in practical scenarios. The contextualization highlights the relevance of the topic in the real world, sparking students' interest and showcasing the applicability of the concepts they will learn.

Problem-Based Situations

1. Imagine a scenario where you are a scientist trying to determine how certain metals react chemically in different environments. How could the concept of oxidation number help in predicting these reactions?

2. Consider a car battery, which operates based on oxidation-reduction reactions. How could knowledge about the oxidation number of the elements involved be used to improve the performance and efficiency of the battery?

Contextualization

The oxidation number is not just a theoretical tool; it has significant practical applications, such as in battery manufacturing, wastewater treatment, and even in medicine, where understanding oxidation reactions can aid in the development of new drugs. Furthermore, the discovery and application of oxidation rules date back to the work of chemists, making this a concept with a rich history in science.

Development

Duration: (65 - 75 minutes)

The Development stage is intended to practically and interactively apply the concept of oxidation number. By engaging students in playful and contextualized activities, the aim is not only to fix the content but also to develop analytical skills, calculation, and teamwork. Each proposed activity is designed to challenge students to think critically and creatively apply knowledge, ensuring a deeper and more lasting understanding of the topic.

Activity Suggestions

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

Activity 1 - The Mystery of the Missing Metals

> Duration: (60 - 70 minutes)

- Objective: Develop calculation and analysis skills of NOX in problem situations, promoting teamwork and the practical application of content.

- Description: In this activity, students will be chemical detectives investigating an intriguing case where different metals have been 'stolen' from a laboratory. Each group will receive clues about the oxidation states of the metals in different compounds, and they will need to calculate the NOX to deduce which metals were used in each mysterious compound.

- Instructions:

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

• Distribute the clue sheets to each group, containing information about the compounds and their respective partial oxidation states.

• Ask each group to calculate the oxidation number of the metals in the given compounds.

• Each group must present their conclusions, explaining how they arrived at their results.

• To make the activity more interactive, allow groups to exchange clues with each other to complete their investigations.

Activity 2 - The Battle of Ions

> Duration: (60 - 70 minutes)

- Objective: Practice calculating and understanding oxidation numbers in a playful and strategic way, stimulating critical thinking and interaction.

- Description: Students will enter a 'battle' where each group represents a different ion in an electrochemical cell. Using cards that represent the gain and loss of electrons (redox), the groups will need to alter the oxidation state of their ions to 'defeat' adversaries, correctly applying the rules of NOX.

- Instructions:

• Organize students into groups of up to 5 participants, each representing a different ion.

• Explain the rules of the battle, where each played card can change the NOX of an ion.

• Distribute a deck of redox cards to each group.

• Initiate the battle, where each round allows groups to play a card to change their NOX or that of the opponent.

• The goal is to achieve an oxidation state that is 'stable' according to the chemical rules, winning the battle.

Activity 3 - The Electron Exchange Fair

> Duration: (60 - 70 minutes)

- Objective: Understand the concept of oxidation and reduction through a practical and interactive approach, enhancing the ability to calculate and apply NOX in various contexts.

- Description: Simulating a fair, students will have to 'negotiate' electrons to balance oxidation-reduction equations. Each group will have a set of substances with different NOX, and they will need to exchange electrons with each other to stabilize the compounds.

- Instructions:

• Divide students into groups of up to 5 people, each group with different chemical compounds.

• Give each group a 'wallet' of electrons that they can use to exchange between compounds.

• Groups must negotiate electron exchanges with other groups to try to balance their redox equations.

• Each exchange must be justified with the correct calculation of NOX before and after the exchange.

• At the end, groups will present their balanced equations and explain their exchange strategies.

Feedback

Duration: (10 - 15 minutes)

The purpose of this discussion stage is to allow students to reflect on what they have learned and verbalize their understanding and any doubts. This exchange of ideas not only reinforces learning but also helps the teacher identify areas that may need review or further explanation. Additionally, by hearing their peers' experiences, students can gain new perspectives and insights into the use of oxidation number.

Group Discussion

After completing the interactive activities, promote a group discussion with all students. Start the conversation by recapping the main concepts covered during the activities, and encourage students to share their experiences and discoveries. Ask how their understanding of the oxidation number has evolved and how they perceive the application of this concept in real situations. This discussion aims to integrate knowledge and consolidate learning through the exchange of ideas among the groups.

Key Questions

1. How did the calculation of oxidation number help you solve the challenges posed in the activities?

2. What were the greatest difficulties faced when applying the oxidation number rules during the activities?

3. How do you imagine the concept of oxidation number can be applied in real situations outside the classroom?

Conclusion

Duration: (5 - 10 minutes)

The purpose of this Conclusion stage is to ensure that students have a clear and consolidated understanding of the lesson topic, connecting all the points discussed and the activities carried out. It is an opportunity for the teacher to emphasize the relevance of oxidation number in practical and theoretical chemistry, and for students to reflect on how the content learned can be applied in different contexts outside the classroom.

Summary

In the conclusion, the teacher should summarize the main points discussed about oxidation number, reiterating how each atom in a compound has an NOX that indicates its oxidation state, and how this affects chemical reactions. It is essential for students to understand that NOX is fundamental to predicting the behavior of elements in various reactions.

Theory Connection

During the class, the connection between theory and practice was established through interactive activities simulating real scenarios where knowledge of NOX is applied, such as in electrochemical cells and redox equations. This demonstrates how theoretical knowledge is essential for practical application and solving real problems.

Closing

Finally, the importance of oxidation number in daily life was highlighted, not only in academic or laboratory contexts but also in industrial and environmental applications, such as in the development of more efficient batteries or the treatment of wastewater, demonstrating the relevance of studying chemistry and its practical applications in everyday life.