Contextualization

Matter can be found in nature in different physical states: solid, liquid, and gaseous, each with its specific properties. However, with the change of some conditions, such as temperature and pressure, it is possible to make matter transition from one state to another. In Chemistry, this phenomenon is known as "change of state" and is essential to understand various natural and industrial processes.

In this project, we will explore in depth the changes of state, a key concept in Chemistry. We will learn to recognize when these changes occur, how they happen, and we will also learn the name of each of these processes. Have you ever thought, for example, how water transforms from ice to liquid and from liquid to vapor? Or how vapor transforms back into liquid when it comes into contact with a cold surface? All of these are changes of state and are essential for the understanding of various natural and industrial phenomena, and even for the operation of some household appliances we use in our daily lives!

Changes of state have applications in various areas, from weather forecasting to the food industry. In meteorology, the evaporation and condensation of water are fundamental concepts to explain weather phenomena, such as cloud formation and the occurrence of rain. In the food industry, freezing and refrigeration are common techniques to preserve food, while boiling is often used in food preparation. Changes of state are also present in the distillation process, used to purify liquids or separate mixtures of liquids with different boiling points.

Below are some resources to introduce you to the concept of changes of state:

1. Physical States and Changes of State - Mundo Educação
2. Physical State Changes - Brasil Escola
3. Physical State Changes: what it is, how it happens, examples - Brasil Escola

Practical Activity: "The Dance of Molecules"

Project Objectives

This project aims to demonstrate the changes of state of matter through a practical experience, stimulating collaboration, teamwork, and creativity among students. The activity is designed for groups of 3 to 5 students and should take between five to ten hours to complete.

Project Description

The project will involve the realization of three practical experiments, each demonstrating a change of state - fusion, vaporization, and condensation. Students will be challenged to record their observations, reflect on the results, and discuss their conclusions in a written report.

Necessary Materials

• Ice cubes
• Pan
• Fire (stove or Bunsen burner)
• Watch glass
• Thermometer
• Stopwatch
• Camera (can be a cell phone) to record the experiments

Step by Step

1. In a safe environment and under adult supervision, place an ice cube in the pan and observe. This is the fusion process: the change from solid to liquid state. Record the time it takes for the ice to completely change to water.

2. Heat the water in the pan until it boils. This is the vaporization process: the change from liquid to gaseous state. Measure and record the temperature at which the water starts to boil and how long it takes for all the water to turn into vapor.

3. Place the watch glass on the pan to collect the vapor. After some time, you will see water droplets forming on the watch glass. This is the condensation process: the change from gaseous to liquid state. Record the time it takes for condensation to start and how many water drops are collected after a certain period.

Project Delivery

The final product of this project will be a written report that will include:

1. Introduction: Provide context on the topic of changes of state and their relevance. Explain the project's objectives.

2. Development: Present the theory of changes of state and explain each process observed in practice (fusion, vaporization, and condensation). Indicate the methodology used and present the results obtained, discussing them in light of the theory. You can include photos of the experiments to enrich your report.

3. Conclusion: Summarize the main findings of the project, what you have learned, and why the results are significant.

4. Bibliography: List the resources you consulted to carry out the project, including books, websites, videos, etc.

This project not only encourages students to be interested in the fascinating world of chemistry but also develops important skills such as teamwork, time management, problem-solving, communication, and creative thinking.