Context

Chemistry is a science that investigates matter and its transformations, describing the composition, structure, and properties of substances, as well as the changes they undergo when interacting with other substances. In this sense, a fundamental concept in chemistry is the molecular formula.

The molecular formula is a representation of the quantity of atoms that make up a certain molecule. It is very useful in the analysis, description, and classification of a variety of chemical compounds, and its determination is often an essential step in understanding and describing the properties and behaviors of complex chemical compounds.

It is important to highlight that the molecular formula provides basic information about the structure of a molecule, but it does not reveal the complete three-dimensional structure of the molecule or the way atoms are bonded. This information can be obtained through a more in-depth study of the properties and behaviors of the compound in question.

The determination of the molecular formula has undeniable relevance in the scientific field, but it also plays an important role in our daily lives. For example, it is essential for the development of medicines and for the chemical industry in general, which produces a wide range of materials and products that we use daily.

In the field of medicine, the molecular formula can be used to develop more effective drugs with fewer side effects. In the food industry, it is used in the creation of food additives to improve the taste and consistency of foods. In the materials industry, the determination of molecular formulas has helped develop new materials with improved properties, such as stronger plastics or more durable textiles.

To delve deeper into the subject, we suggest consulting the following links:

1. Molecular Formula - Mundo Educação
2. How to Calculate the Molecular Formula - Brasil Escola
3. Molecular Formula - Toda Matéria

Practical Activity - "Determination of Molecular Formula through Card Game"

Project Objective

The objective of this project is to understand concepts such as molar proportion and molecular formula through a collaborative card game.

Detailed Project Description

Students will be divided into groups of 3 to 5 people. Each group will represent a "chemical company" and the goal will be to build molecules using "element cards". Each element card will have a chemical element, its symbol, and its atomic number.

The activity should be carried out over a week, with students having a total of 2 to 4 hours to work on the project. They will have to manage their time, communicate effectively, and solve problems as a team.

Required Materials

• Cards (each representing a chemical element).
• Paper and pen for notes.
• Chemistry book or internet access for reference.

Detailed Step-by-Step for Activity Execution

1. Distribute the element cards among the groups. Each group should receive an equal number of cards.
2. The groups should then start "building" molecules by combining the element cards. Each combination should represent a valid molecular formula.
3. The groups should, in parallel, take notes on the molecules they are building, including information about the molecular formula, the name of the molecule, and the molecule's properties (if known).
4. At the end of the activity, each group should have a list of molecules they built, along with the associated information.
5. Each group will then prepare a report of their findings. This report should contain an Introduction section (detailing the relevance and application of the topic in the real world), Development (explaining the theory behind the main theme of the project, the activity in detail, and presenting and discussing the results obtained), Conclusions (explaining the learnings and conclusions drawn from the project), and Bibliography (indicating the sources consulted for the project).
6. The groups will make a final presentation of their projects to the class, explaining the molecules they built and the importance each of them has in different contexts in society.

Project Delivery

The group must submit a written final report, where they explain the entire process of building the molecules, the concepts of molar proportion, and how each molecule is represented by a molecular formula.

In the Introduction, they should contextualize the molecular formula topic, explore its relevance in the real world, and explain the objective of the card game. In the Development, they should detail the theory behind the calculation of the molecular formula, explain the activity carried out, discuss the methodology used, and present the results. In the Conclusion, they should summarize the main points of the report, explain what they learned, and draw conclusions from the project. In the Bibliography, they should list all the sources consulted for the project.