Context
Gases play an extremely important role in our daily lives. From breathing to air conditioning systems, from bicycle tires to our climate, gases are everywhere. Chemistry, the discipline that studies matter and its transformations, provides us with tools to understand gases, their properties and behavior, and represents an essential foundation for a variety of related fields.
Matter can exist in four main states: solid, liquid, gaseous, and plasma. Among these, gases represent an interesting category, as their properties are not as intuitive as those of solid and liquid states. To understand gases, their characteristics, and associated theories, we need to fundamentally rely on the gas laws, which relate pressure, volume, temperature, and quantity of gas and form the basis of the kinetic theory of gases.
This theory allows us to deepen our understanding of gases, differentiating ideal gases from real ones and considering the conditions under which a real gas can behave like an ideal gas. Furthermore, the kinetic theory of gases provides a bridge to the concepts of thermodynamics, which describe the energy transfers that occur in chemical reactions.
Gases have a remarkable relevance in everyday life and also in various areas of science. The atmosphere that surrounds us is a mixture of gases that plays a fundamental role in sustaining life on Earth. Understanding the properties of gases is also essential in medicine, for example, in calculating gas mixtures used in anesthesia. Additionally, the industry uses various gases in its processes, such as oxygen in steel manufacturing and nitrogen in food preservation.
Below are the resources that can be used to start studying the topic:
- Gas Properties - Brazil School
- Kinetic Theory of Gases - Stoodi
- Chemical Bonds and Gas Properties - Khan Academy
Practical Activity
Activity Title: Exploring the Properties of Ideal Gases - The Ideal Gas Law
Project Objective:
Investigate and understand the relationship between pressure, volume, and temperature using the ideal gas law as a theoretical basis. Additionally, develop practical and analytical skills, including data manipulation and project report preparation.
Detailed Project Description:
Students will conduct a simple experiment using common materials to observe and analyze the properties of gases. The activity will focus on the practice of the ideal gas law (PV = nRT) and comparing the results obtained with the expected theoretical results.
Required Materials:
- Latex balloons (3 units)
- Ruler (1 unit)
- Thermometer (1 unit)
- Tape measure (1 unit)
- String (1 unit)
Step-by-Step Guide for Activity Execution:
Step 1: Divide the classroom into groups of three to five students.
Step 2: Distribute the necessary materials to each group.
Step 3: Each group should inflate a balloon to a size that can be measured with the ruler (e.g., 10 cm in diameter) and measure the room temperature with the thermometer.
Step 4: The group should record the temperature and the volume of the balloon. The volume of the balloon can be estimated by applying the formula for the volume of a sphere (4/3 * π * radius^3), considering the radius as half of the balloon's diameter.
Step 5: Inflate the balloon a bit more, and the new diameter measurement and room temperature should be recorded again.
Step 6: The group will repeat step 5 two more times, thus obtaining five sets of data (one from step 3 and four from step 5).
Step 7: Each group will then analyze their data trying to find a relationship between volume and temperature. They should verify if their data align with the ideal gas law.
After completing the practical activity, each group should prepare a report with the following structure and contents:
Report
Introduction:
The group should contextualize the experiment conducted, briefly explaining the importance of studying gases, the ideal gas law, and the experiment's objective.
Development:
The group should detail the experiment procedure, describe the results obtained, and discuss whether these results are in line with the theory of ideal gases.
Conclusion:
The group should summarize the main points of their experiment, discuss what they learned from the activity, and draw conclusions from the project.
Bibliography:
The group needs to indicate the sources of information used, such as books, websites, videos, etc.
Students will have one week to complete this activity, which includes conducting the experiment and producing the report. The estimated workload is between two to four hours per student.
