Lesson Plan | Traditional Methodology | Introduction to Organic Chemistry: Organic Series

Objectives

Duration: (10 - 15 minutes)

The aim of this stage of the lesson plan is to establish a solid foundation for understanding what organic series are and how they are classified. By clearly outlining the objectives, students will have a clear vision of what is expected of them, facilitating their focus and understanding of the content to be covered.

Main Objectives

1. Understand the concept of organic series in chemistry.

2. Recognize and differentiate isologous, homologous, and heterologous series.

3. Identify compounds belonging to an organic series.

Introduction

Duration: (10 - 15 minutes)

The purpose of this stage of the lesson plan is to capture students' attention by contextualizing the topic in a relevant and interesting way. By presenting practical examples and curiosities, students will be more receptive to the content and understand the importance of studying organic series.

Context

Start the lesson by contextualizing the importance of Organic Chemistry in daily life. Explain that Organic Chemistry is the area of Chemistry that studies carbon compounds, which are the basis of life. Highlight that many materials we use daily, such as plastics, medicines, fuels, and foods, are organic compounds. Emphasize that understanding organic series helps to better comprehend the structure and properties of these compounds.

Curiosities

Did you know that aspirin, one of the most common medicines in the world, is an organic compound? It is part of an organic series called carboxylic acids. The ability to synthesize and modify these compounds has allowed significant advances in medicine, improving the quality of life for millions of people.

Development

Duration: (45 - 50 minutes)

The aim of this stage of the lesson plan is to provide a detailed and in-depth understanding of the concepts of organic series, including homologous, isologous, and heterologous series. Through clear explanations, visual examples, and practical exercises, students will be able to recognize and differentiate these series, as well as identify compounds belonging to each of them.

Covered Topics

1. Concept of Organic Series: Explain that organic series are groups of compounds that have a similar chemical structure and similar chemical properties. Each series has a specific functional group and varies only by the repetition of structural units. Use visual examples to illustrate the structure of different series. 2. Homologous Series: Detail that homologous series are composed of molecules that differ from each other by a fixed number of CH2 units. Each member of the series has gradual and predictable physical properties. Example: Alkanes (methane, ethane, propane). 3. Isologous Series: Describe that isologous series are those whose compounds have the same molecular formula but differ in how the atoms are arranged. This can result in different physical and chemical properties. Example: Isomers of butane (n-butane and isobutane). 4. Heterologous Series: Explain that heterologous series are composed of molecules that have different molecular formulas but a similar functional group. This results in similar chemical properties but different physical properties. Example: Carboxylic acids and esters. 5. Identification of Compounds: Teach how to identify compounds within an organic series by analyzing their chemical structures and functional groups. Provide practical examples and guided exercises to solidify understanding.

Classroom Questions

1. Identify and write the structural formula of the first three members of the homologous series of alcohols. 2. Explain the structural difference between n-butane and isobutane. Illustrate their structural formulas. 3. Given the compound methyl acetate (C3H6O2), determine the organic series it belongs to and explain the characteristics of that series.

Questions Discussion

Duration: (20 - 25 minutes)

The purpose of this stage of the lesson plan is to review and reinforce the concepts covered, ensuring that students have understood the content well. The detailed discussion of the answers allows clarifying questions and consolidating learning, while engagement questions encourage active participation from students and the practical application of acquired knowledge.

Discussion

• Identify and write the structural formula of the first three members of the homologous series of alcohols. Methanol (CH3OH): The simplest of the alcohols, with a hydroxyl group (-OH) attached to one carbon. Ethanol (C2H5OH): An alcohol with two carbons, one of which is bonded to the hydroxyl group. Propanol (C3H7OH): Has three carbons, one of which is connected to the hydroxyl group.

• Explain the structural difference between n-butane and isobutane. Illustrate their structural formulas. n-Butane (C4H10): A linear chain of four carbons. Isobutane (C4H10): A branched chain, where three carbons form a main chain and the fourth carbon is attached to the central carbon. Structural Formulas:

  • n-Butane: CH3-CH2-CH2-CH3
  • Isobutane: (CH3)2CH-CH3

• Given the compound methyl acetate (C3H6O2), determine the organic series it belongs to and explain the characteristics of that series. Organic Series: Esters. Characteristics: Esters possess a functional group R-COO-R', where R and R' are hydrocarbon chains. They are often formed by the reaction between a carboxylic acid and an alcohol and have characteristic aromas, used in fragrances and flavorings.

Student Engagement

1. ❓ Why do compounds in a homologous series exhibit gradual physical properties? 2. ❓ How does the structural difference between isomers affect their physical and chemical properties? 3. ❓ What are some practical applications of esters in daily life? 4. ❓ Describe an example of how organic chemistry, specifically knowledge of organic series, can be applied in the pharmaceutical industry.

Conclusion

Duration: (10 - 15 minutes)

The aim of this stage of the lesson plan is to summarize and consolidate the main points covered, reinforcing students' understanding. By recapping the content and demonstrating the connection with practical applications and the relevance of the topic, students can integrate knowledge in a more solid and contextualized way.

Summary

• Concept of organic series and its importance.
• Definition of homologous series: compounds that differ by a fixed number of CH2 units.
• Definition of isologous series: compounds with the same molecular formula but different atomic arrangements.
• Definition of heterologous series: compounds with different molecular formulas but similar functional groups.
• Methods for identifying compounds within an organic series.

The lesson connected theory with practice by using visual examples and guided exercises to illustrate and solidify the concepts of organic series. Through practical examples, such as the structure and properties of methanol and isobutane, students were able to visualize how small differences in chemical structure result in changes in the physical and chemical properties of compounds.

Knowledge of organic series is essential to understanding the chemistry of carbon compounds, which are the basis of life and an essential part of our daily lives. For example, the ability to synthesize and modify organic compounds such as medicines and plastics has a direct impact on health, technology, and industry. Understanding organic series allows the application of this knowledge in various areas, such as producing fragrances and flavorings through the synthesis of esters.