Introduction

Salt is such a common everyday component that we often do not stop to reflect on its importance and complexity. A salt, in chemical terms, is the product of a reaction between an acid and a base. The substance most commonly known as salt is sodium chloride, the product of the reaction between hydrochloric acid and caustic soda. This is the salt we use to season food, but there are many other types of salts with their own characteristics and properties.

Salts can be classified in various ways. They can be simple, when formed by only two elements, or compound, when formed by more elements. Salts can be neutral, acidic, basic, double, mixed, etc. And each of these types has its own properties and uses.

Different salts have different uses in industries and everyday life. For example, sodium and potassium salts are used in the manufacture of soaps and detergents. Table salt is widely used in cooking. And even in construction, calcium chloride is used to accelerate the curing time of concrete.

Contextualization

We live in a world where salt is present in various forms and in many aspects of our daily lives. In food, the food industry uses salt not only to add flavor but also as a preservative. In health, salt is used both in the treatment and prevention of a series of diseases. In nature, many animals depend on salt to survive, either to regulate body fluids or to build structures like shells.

The exploration and production of salt also have enormous historical and economic importance. Several ancient civilizations, such as the Egyptians and the Romans, already extracted and traded salt. To this day, in many places around the world, salt production is an important economic activity, either by direct extraction from natural salt flats or by the evaporation of seawater.

To delve deeper into the topic, I suggest the following sources:

1. Toda Matéria: What is salt
2. Mundo Educação: Salts
3. Brasil Escola: Classification of salts
4. InfoEscola: Salt (NaCl)
5. Canal Fala Química: Types of Salt

Practical Activity: "Salt in Everyday Life"

Project Objective

The objective of the project is to investigate the presence and importance of salt in everyday life and industry, as well as to understand and differentiate various types of salts and their properties. Thus, it is possible to explore the application of chemical concepts in daily life.

Detailed Description

Students, divided into groups of 3 to 5, should work together to research and document information about salt and its presence in our daily lives.

Each group should choose one of the following topics to delve into:

• Use of salt in cooking
• Use of salt in health
• Use of salt in industry
• Extraction and production of salt
• Salts used in construction

Students should research the type(s) of salt(s) involved in the topic, the properties of this/these salt(s) that make it/them suitable for this use, and how the salt is obtained or produced.

Necessary Materials

• Internet access for research
• Notebook or sheet of paper for notes
• Pen or pencil
• Computer to write the report

Step by Step

1. Form groups of 3 to 5 students.
2. Each group chooses one of the suggested topics.
3. The groups conduct research on the internet and in books to learn about the use of salt in their chosen topic and the types of salts involved.
4. Students should understand and explain which properties of these salts make them suitable for this use.
5. Students should also research how these salts are obtained or produced.
6. Each group should then write a detailed report on their findings.

Project Deliverables and Document Writing

After the practical research, each group should write a report containing:

1. Introduction: a brief description of the chosen topic and why it is relevant to study the role of salt in this context.
2. Development: Detailed description of the type of salt involved, its properties, and how it is produced or obtained. Explain why this property of the salt is important for the topic under discussion. Indicate the research methodology.
3. Conclusions: Based on their findings, students should discuss the importance of salt in everyday life and industry, express their learnings and conclusions about the project.
4. Bibliography: List all sources used for research.

The report should be about 3 to 5 pages of text, excluding images, graphs, tables, or the bibliography. It should be delivered in digital and printed format within a week from the start of the project.

Students should pay attention to the clarity and organization of their ideas, grammatical correctness, the adequacy of the text to the proposed theme, and the appropriate use of the consulted sources.

It is expected that at the end of the project, students will have developed technical and socio-emotional skills, such as time management, research and academic writing, teamwork, and presenting a topic clearly and informatively.