Contextualization

Chemistry, as a science, explores and describes the nature and transformations of matter, making it fundamental in our daily lives, in areas such as medicine, agriculture, industry, environment, among others. In this project, we will focus on the study of an important group of organic compounds, hydrocarbons.

Hydrocarbons are compounds formed exclusively by carbon and hydrogen atoms. They can be classified into two main categories, according to how the carbon atoms are connected: aliphatic hydrocarbons and aromatic hydrocarbons. Aliphatic hydrocarbons can be subdivided into saturated hydrocarbons (alkanes and cycloalkanes) and unsaturated hydrocarbons (alkenes, alkynes, and dienes). Aromatic hydrocarbons have a benzene ring or related structures in their composition.

The study of hydrocarbons and their derivatives is essential due to their wide presence in different contexts. They are present in fuels, medications, plastics, dyes, among others. They have high economic importance, being the basis of petrochemical and pharmaceutical industries. Furthermore, the study of these molecules and their reactions is essential to understand various environmental issues, such as the formation of atmospheric pollutants.

Understanding the properties and reactions of hydrocarbons allows for the development of new materials and medications, more efficient energy production, and proposing solutions to environmental problems. For example, understanding the structure and reactivity of hydrocarbons has led to the development of catalysts for reducing vehicle emissions, which is extremely important for reducing air pollution.

To delve deeper into this subject, I suggest the following study materials:

• Book: Chemistry Annex I - Volume 4, Parameters Series, Module I - Hydrocarbons (Brazil. Ministry of Basic Education. Brasília: MEC/SEF, 2001).
• Video: "Hydrocarbons - What are they and what are they used for?", from the Manual do Mundo channel on YouTube.
• Website: Mundo Educação, Organic Chemistry section.

Practical Activity

Activity Title: "Building Hydrocarbon Models"

Project Objective

This project aims to allow students to investigate, in a practical and playful way, hydrocarbons. Students will build three-dimensional models of different hydrocarbons, which will allow them to visualize the structures of these molecules and their different categorizations.

Detailed Activity Description

Groups should research different types of hydrocarbons (alkanes, alkenes, alkynes, cycloalkanes, and aromatics) and choose five of them to model using materials they have at home such as modeling clay, toothpicks, barbecue sticks, Styrofoam balls, and other creative materials. Each chosen hydrocarbon must be from a different category.

Required Materials

• Modeling materials (Styrofoam balls, modeling clay, toothpicks, straws, barbecue sticks, etc)
• Textbooks, internet, or other research materials
• Paper and pencil for notes

Detailed Step-by-Step for Activity Execution

1. Divide the class into groups of 3 to 5 students.
2. Each group should research the concept of hydrocarbons and their types, using the study materials suggested in the introduction or others of their preference.
3. The groups should choose five different hydrocarbons (one of each type: alkane, alkene, alkyne, cycloalkane, and aromatic) to model.
4. Using the modeling materials, the groups should build molecular models of the five chosen hydrocarbons.
5. Each group should take photos of the created models and prepare an explanatory presentation about each hydrocarbon (structure, properties, uses, etc.), including the photos of the constructed models, for the final submission.

Project Deliverables

The project will be delivered in the form of a written report prepared by the students following the following sections:

1. Introduction: In this section, students must contextualize the theme "Hydrocarbons", its relevance and application in the real world, as well as the objective and importance of this project.

2. Development: Here, students must explain the theory about hydrocarbons, detail the activity performed, including the methodology used, and finally, present and discuss the results obtained. The photos of the five constructed models should be included in this section, along with an explanation of each hydrocarbon, including its structure, properties, and uses. It is important for the groups to explain how they arrived at the constructed model.

3. Conclusion: Students should conclude the work by summarizing their main points, and explaining the learnings obtained and the conclusions drawn from the project.

4. Bibliography: Students should indicate the sources they relied on to develop the project such as textbooks, web pages, videos, etc.

This practical activity will not only allow students to better understand the concept of hydrocarbons and their varieties, but will also develop teamwork, research skills, and information synthesis of the students.