Context

Chemistry is the science responsible for studying matter, its properties, how substances interact, and the transformations that occur during these interactions. Within this broad field of study, we have an extremely important theme for understanding a large part of chemical phenomena: concentration units.

These units are used to express the amount of a substance (solute) dissolved in a certain volume of another substance (solvent), forming a solution. In addition, understanding these units is essential to comprehend the relationships between different ingredients in a recipe, the dosage of medications, the quality of the air we breathe, the quality of the water we drink, among many other examples of practical applications.

Although the most common concentration units are molarity, molality, and normality, there are other units that are used in specific contexts and are equally important. These units include molar fraction, mass percentage, volume percentage, parts per million (ppm), parts per billion (ppb), and parts per trillion (ppt).

To better understand these other concentration units, I suggest that students use the following reliable sources as a basis for further study:

1. Brazil School: Concentration Units
2. World Education: Other Concentration Units
3. Khan Academy (in Portuguese): Solution Concentration Units

Practical Activity: "Game of Concentrations"

Project Objective

The project's objective is to provide students with a practical and playful experience in studying different concentration units. Through the creation of an educational game activity, students will have the opportunity to understand the concept of solution concentration, as well as practice the calculation and conversion between different concentration units. Additionally, the project encourages teamwork, time management, creativity, and communication.

Detailed Project Description

Students, divided into groups of 3 to 5 people, should create a "Game of Concentrations" involving the preparation of solutions of different concentrations and a set of challenges related to the interpretation and calculation of concentrations.

The created game should be complex enough to involve at least four different concentration units (e.g., ppm, ppb, ppt, molar fraction, mass or volume percentage) and should integrate concepts from another discipline, such as mathematics or biology.

The activity should be planned and structured to require more than twelve hours per participating student to be executed, including the game planning phase, solution preparation, challenge creation, and final report writing.

Required Materials

1. Transparent containers for preparing and storing solutions
2. Substances to prepare the solutions (salt, sugar, food coloring, etc.)
3. Distilled water
4. Scale for measuring mass
5. Graduated cylinders or pipettes for measuring volume
6. Materials for making the game (paper, colored pens, cardboard, etc.)
7. Computer with Internet access for research and report elaboration

Detailed Step-by-Step for Activity Execution

1. Game Planning: Students should plan the game, defining the rules, challenges, board design (if applicable), and other game components. The game should be designed to last approximately 30 to 45 minutes.

2. Solution Preparation: Students should prepare the solutions to be used in the game, following safety principles in handling chemical substances.

3. Challenge Creation: Students should create a set of challenges that players must solve during the game. These challenges should involve the interpretation and calculation of solution concentrations.

4. Report Elaboration: After completing the game, students should elaborate a detailed report on the project, following the provided guidelines.

Project Delivery

After completing the practical activity, students should prepare and present a report that includes the following topics:

1. Introduction: Contextualization of the theme, relevance and practical application, project objectives.

2. Development: Discussion of the theory on the concentration units used, detailed explanation of the game rules, solution preparation, and challenges created, description of the methodology used, presentation and discussion of the results.

3. Conclusion: Recap of the main points, lessons learned, conclusions drawn from the project.

4. Bibliography: References consulted for the project execution.

This final document should fit and complement what students worked on in the practical project, in order to consolidate the theoretical understanding of concentration units and demonstrate their ability to communicate and explain the chemical concepts involved.