Contextualization and Introduction

Bases are substances that, in aqueous solution, release the hydroxide ion (OH-), according to Arrhenius' theory. They can also be classified according to their ionization capacities into strong bases (which completely ionize in water) and weak bases (which partially ionize in water). Furthermore, bases are classified based on their solubility, being able to be soluble, called alkaline hydroxides, and insoluble, known as alkaline-earth hydroxides. Therefore, understanding and differentiating these characteristics is fundamental for the understanding of basic chemistry.

Moreover, bases are a fundamental part of various everyday and industrial processes. They are used in cleaning solutions, in paper manufacturing, in acid neutralization processes, among other applications. This demonstrates the relevance of understanding what bases are, how they work, and where they are used.

Bases are also of paramount importance within the human body. The maintenance of blood pH, for example, is a process that involves bases and is vital for survival. Understanding how bases act in biochemistry can help understand various bodily processes, as well as the action of some medications.

For a better understanding of the concept of bases and their properties, I recommend the book "General Chemistry and Chemical Reactions", by John C. Kotz, Paul M. Treichel, and John Townsend. In addition, the websites Brasil Escola and Mundo Educação have articles that are easy to understand and quite comprehensive on the subject. I also recommend the class by Professor André Paes Leme, available on YouTube, for a didactic and enjoyable explanation.

Practical Activity

Title: "Demystifying Bases: Where Do Bubbles Come From?"

Project Objective

The objective of this project is to experimentally understand the properties of bases, focusing mainly on their interaction with acids and gas production. We also want students to develop the socio-emotional, collaborative, and technical skills described earlier.

Project Description

In this project, students will conduct an experiment to verify the reaction between bases and acids. In addition, they should develop the chemical explanation of the observed result, based on the theory learned.

Groups should consist of 3 to 5 students, and the total duration of the project will be 1 month, with an estimated 5 to 10 hours dedicated by each student to project execution.

Required Materials

1. Sodium bicarbonate (NaHCO3)
2. Hydrochloric acid solution (HCL) - 0.1 M
3. 250 ml Erlenmeyer flask
4. Butane gas in a can (culinary use)
5. Matches or lighter
6. Safety goggles

Step by Step

1. Put on safety goggles, as we will be dealing with reactions that can produce gases and splashes.

2. Add two teaspoons of sodium bicarbonate to the Erlenmeyer flask.

3. Then, slowly add the acidic solution until the bubbles stop being produced. Be careful not to add too much and overflow the flask.

4. Observe the flask, what happens when the acid is added to the sodium bicarbonate?

5. After the reaction is complete (no more bubble formation), use the butane gas to fill the Erlenmeyer flask with gas. Be careful not to let the gas escape.

6. Step back safely from the flask and light the lighter or match near the mouth of the flask. Observe what happens.

Project Deliverables

At the end of the project, the group must submit a report containing the following sections:

1. Introduction: Provide context for the project, its relevance and real-world application, and the objective of this project.

2. Development: Explain the theory of bases and acids and how this theory applies to the experiment conducted. Explain the experiment in detail, indicating the methodology used, and present and discuss the results obtained.

3. Conclusion: Conclude the work by summarizing its main points, explaining the learnings obtained, and drawing conclusions about the project.

4. Bibliography: List the sources you relied on to work on the project such as books, web pages, videos, etc.

Remember that the report is an essential part of the project and should reflect the teamwork, the learnings obtained, and the practical application of the concepts learned in the classroom.