Contextualization

Introduction

Chemistry is a science that explores the composition, structure, and properties of substances (chemical elements and compounds), as well as the transformations they undergo. It is a vast and fascinating field, the understanding of which is essential for us to appreciate the world around us. In this project, we will specifically focus on the theme of 'Substances and Mixtures'.

'Substances and Mixtures' is a fundamental topic in Chemistry, as it serves as the basis for understanding other areas of the discipline, such as chemical reactions and thermodynamics. A substance, in chemical terms, is a type of matter with a defined chemical composition and specific characteristics. On the other hand, a mixture is composed of two or more substances that are physically combined, not chemically.

We will explore the different types of substances and mixtures, how they can be characterized, and what physical and chemical processes are used to separate them. Additionally, we will learn to differentiate pure substances from mixtures, as well as to identify the different types of substances and mixtures.

Contextualization

This theme is of utmost importance for many practical and real-world applications. Understanding substances and mixtures is fundamental in various fields, from the food industry, where the mixing of ingredients leads to the formation of new foods, to the pharmaceutical industry, where the creation of medicines involves the precise mixture of various substances.

On the other hand, knowing how to differentiate and characterize substances and mixtures has a significant impact on our daily lives. For example, the water we drink daily is a pure substance, while the air we breathe is a mixture of gases. Understanding this can help us better understand the properties of these materials and how they react under different conditions.

Practical Activity

Activity Title: 'Exploring Substances and Mixtures: From Theory to Practice'

Project Objective

The objective of this project is to provide students with a practical laboratory experience, allowing them to explore the theoretical concepts of substances and mixtures. Additionally, the project aims to improve teamwork skills, time management, proactivity, and creative thinking.

Detailed Project Description

This activity will involve the identification and separation of substances and mixtures using laboratory techniques. Teams must identify the substances present, plan and execute a method to separate the mixtures, record their observations, and finally engage in scientific reporting, integrating the disciplines of Chemistry and Portuguese Language.

The groups, composed of 3 to 5 students, will receive an unknown sample composed of a mixture of substances. The challenge will be to identify the substances present in the mixture through research and experiments and then develop an efficient and effective method to separate these substances.

The activity will be divided into two main stages:

1. Investigation Phase: Students will investigate the provided sample, using various methods to identify the substances present. They will research suitable separation methods and plan their approach.

2. Experimentation Phase: Students will execute the planned separation method, carefully documenting their observations and recording any difficulties or challenges faced.

This project will be carried out over three weeks, with students working in their respective teams.

Required Materials

The following materials will be needed to carry out this project:

• Unknown sample (provided by the teacher)
• Access to the Chemistry laboratory
• Various laboratory equipment (test tubes, beakers, pipettes, etc.)
• Materials for documentation (notebook, camera)
• Internet access for research
• Pencils and paper for planning
• Personal Protective Equipment (PPE)

Detailed Step-by-Step

1. Group Formation and Project Presentation: Students will form groups of 3 to 5 people, and the teacher will present the project, its objectives, and requirements.

2. Investigation Phase:

   • Sample Analysis: Students must make preliminary observations of the sample, recording colors, textures, smells, etc. They should research possible substances that match their observations.
   • Sample Testing: Students will perform various tests on small samples, such as solubility tests, to help identify the substances present.
   • Separation Planning: Based on their findings, students should then research and plan a method to separate the identified substances.

3. Experimentation Phase:

   • Plan Execution: Students will then carry out the planned separation, carefully documenting the process and any observations.
   • Results Evaluation: After the separation, students will compare the final results with their initial predictions, reflecting on any discrepancies and learnings.

4. Final Report Elaboration:

   • Documentation Review and Analysis: Students will review the documentation collected during the project and analyze the results.
   • Report Writing: Students will then write the final report, including introduction, development, conclusions, and bibliography used.

Project Deliverables

At the end of the project, each group must deliver:

1. Final Report: This document should contain an introduction to the topic, the development of the activity, conclusions, and the bibliography used as detailed in the previous topics. The report should demonstrate the connection between the studied theory and its practical application, as well as provide an in-depth discussion of the results obtained.

2. Oral Presentation: Each group will make a 10-15 minute oral presentation summarizing their project, where they will discuss the separation process they chose, the challenges encountered, the resolution strategies, and the results obtained.

Note on Document Writing: The report should be written clearly and concisely, using appropriate scientific terminology. Students should strive to explain their methodology, observations made, and results obtained clearly. Additionally, the report should include a conclusions section that synthesizes what students learned during the project and how these learnings connect with the concepts studied in the classroom.