Contextualization

Chemistry is a science that allows us to understand the world around us, from the food we eat, the water we drink, to the medications we take. Every substance we experience and interact with in our daily lives is a complex molecular combination that has been understood and explained through Chemistry.

And one of the fundamental concepts of Chemistry is that of solutions. Solutions are homogeneous mixtures of two or more substances, in which one (the solute) is dispersed in another (the solvent). You probably come across solutions several times a day, whether sweetening your coffee with sugar, preparing an orange juice, or taking a medication diluted in water.

They are classified according to the state of saturation: unsaturated, saturated, and supersaturated solutions, each with distinct characteristics and applications, which we will address in this project.

Importance and Application

Understanding solutions, their classifications, and how they interact is crucial not only for Chemistry but for many areas of science and industry. In medicine, for example, the concentration of a medicinal solution can mean the difference between health and disease; in the food industry, understanding solutions is crucial for the manufacturing process of many products.

Furthermore, understanding solutions allows us to comprehend everyday phenomena. Why does juice dissolve more easily in cold water than in hot water? How does salt melt ice on roads during winter? All these questions are linked to our understanding of solutions and their interaction with the environment.

Practical Activity: Introduction, Observation, and Comparison of Types of Solutions

Project Objective

The objective of this project is to provide students with the opportunity to study the theoretical concepts of types of solutions and the practical observation of these concepts, as well as the discussion and comparison of the results obtained. Students will work in groups of 3 to 5 members.

Project Description

Students will prepare three types of solutions (unsaturated, saturated, and supersaturated) and will perform quantitative and qualitative measurements of them. They will then discuss and compare their observations, prepare a report, and present the results to the class in a creative presentation.

Required Materials

• 3 250 ml beakers
• Water
• Salt (NaCl)
• Scale
• Magnetic stirrer or spoon
• Bunsen burner or heating plate
• Thermometer

Step by Step

1. Each group should weigh 50g of salt using the scale.
2. Add water up to the 200ml mark in the three beakers.
3. Add the salt to the first beaker, stirring until the salt is no longer visible. This will be the unsaturated solution.
4. In the second beaker, add the salt gradually, stirring until the salt no longer dissolves. This will be the saturated solution.
5. Heat the water in the third beaker and repeat the process from the second beaker until no more salt dissolves. Then, let the solution cool without stirring. This will be the supersaturated solution.
6. Observe and record the characteristics of each solution, including color, transparency, visible crystals, etc.
7. Compare the solutions and discuss the observations.

Project Deliverables

Students should prepare a project report, which should include the following topics:

1. Introduction: Contextualization and relevance of the study of solutions in chemistry and everyday life. Description of the objective of this project.

2. Development: Detailed explanation of the theory of types of solutions. Step-by-step description of the activity performed, including the methodology used. Presentation and discussion of the results obtained.

3. Conclusion: Recapitulation of the main points of the project and the observations made. Discussion of the learnings obtained and conclusions on how the observations confirmed (or not) the theory studied.

4. Bibliography: List of information sources used for the project.

In addition, the group should prepare a 15 to 20-minute presentation to present the results to the class. The presentation should be creative and interactive, aiming to engage the audience and facilitate the understanding of the concepts studied.

This project should be completed in one month, and a work schedule should be created by the group to ensure that all tasks are completed on time. The collaboration of all group members is essential for the success of the project.