Contextualization

Introduction to the Number of Moles

The number of moles, usually abbreviated to 'mol', is one of the most fundamental units of measurement in chemistry. The term is used to count particles and is based on the number of atoms in 12 grams of carbon-12. This quantity is known as Avogadro's number, named in honor of the scientist Amedeo Avogadro, and is equal to 6.02 x 10²³ particles per mole.

The concept of mole is useful because it allows us to convert between the submicroscopic world of atoms and molecules, and the macroscopic world of everyday experience. Knowing how many atoms or molecules we have in a substance allows us to make predictions about how it will behave and react. Furthermore, it allows us to compare quantities of reactants and products involved in chemical transformations, establishing the ratio between their masses.

The mole is not just a unit of measurement, it is the 'bridge' between theory and practice, where we can take what we know about chemistry at the atomic level and apply it to real-world situations.

Importance of the Concept of Moles

In the real world, the concept of moles plays a crucial role in many different fields, including the chemical industry, pharmaceuticals, medicine, and scientific research. It is used to determine the correct proportions of reactants and products in chemical reactions, making possible the mass production of chemicals, medicines, and many other materials.

The mole is also essential for scientific research, as it allows scientists to manipulate and study atoms and molecules on a scale that would otherwise be unimaginable. This enables the advancement of chemistry, biology, geology, and many other fields of science.

Practical Activity

Activity Title: Building the Mol

Project Objective:

Integrate the concept of mole with practice, allowing students to tangibly experience the theoretical content. Students will build a visual model representing a mole of various substances. The activity involves a significant amount of calculation, collaboration, and creativity.

Detailed Project Description:

Student groups will be responsible for choosing a substance (e.g., water, oxygen, sulfuric acid, etc.) and creating a three-dimensional representation of a mole of that substance. To do this, students will need to calculate the number of atoms, the mass of the substance, and the volume that substance would occupy. The representation needs to be tangible; students can use any material for its construction (Styrofoam, cardboard, clay, etc.). Creativity will be a key factor in dynamically and visually representing what a mole of that substance would be.

Required Materials:

• Calculator
• Periodic Table
• Construction materials for the mole (paper, cardboard, clay, Styrofoam balls, toothpicks, glue, paint, etc.)

Step-by-step guide for the activity:

1. First, students need to choose a substance. This can be an element, such as oxygen, or a compound, such as water.
2. Next, students need to research and calculate how many atoms of each type are present in a mole of the chosen substance. They will need to use the Periodic Table to find the molar mass of each atom and multiply that by the number of atoms to find the total molar mass of the substance.
3. Based on this calculation, students need to create a three-dimensional representation of a mole of their substance. They can use any material they wish, but they should try to make their representation as accurate as possible.
4. Students will present their representations to the class, explaining the substance they chose, how many atoms of each type are present, the mass of a mole of the substance, and how they created their representation.
5. Each group must write a detailed project report, including all calculations performed, a description of the created representation (with photos), an explanation of the chosen substance, and a discussion of the results.

Project Deliverables:

Written Document:

After completing the practical part of the project, students must write a report detailing the project. The structure of this report is as follows:

• Introduction: The student must contextualize the theme, its relevance and application in the real world, as well as the objective of this project.
• Development: The student must explain the theory behind the concept of moles, detail the activity, indicate the methodology used for building the model and for the calculations, and finally present and discuss the results obtained.
• Conclusion: The student must conclude the work by summarizing its main points, explaining the learnings obtained, and drawing conclusions about the project.
• Bibliography: The student must indicate the sources they relied on to work on the project such as books, web pages, videos, etc.

In addition to the report, groups must deliver the three-dimensional representation of the created mole. This will be evaluated based on accuracy, creativity, and the explanation provided by the students.